Title:
ANTIREFLECTION FILM, AND OPTICAL ELEMENT AND OPTICAL SYSTEM HAVING THE SAME
Document Type and Number:
Japanese Patent JP2014174207
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an antireflection film which has high antireflection performance with regard to substrates having various refractive indices and which can reduce generation of ghosts or flares, and to provide an optical element and an optical system having the antireflection film.SOLUTION: The antireflection film comprises 8 layers stacked on a substrate having a refractive index ns. Under the conditions of a reference wavelength λ set to 587.6 nm and ns satisfying 1.40≤ns≤2.15, refractive indices n1, n2, n3, n4, n5, n6, n7 and n8 and optical film thicknesses d1, d2, d3, d4, d5, d6, d7 and d8 of the first, second, third, fourth, fifth, sixth, seventh and eighth layers, respectively, satisfy the respective conditions within predetermined ranges; and an average refractive index nM of n1, n3, n5 and an average refractive index nH of n2, n4, n6 satisfy nH-nM≤0.67.
Inventors:
AMANO SAYOKO
UCHIDA KAZUE
MOMOKI KAZUHIKO
UCHIDA KAZUE
MOMOKI KAZUHIKO
Application Number:
JP2013044284A
Publication Date:
September 22, 2014
Filing Date:
March 06, 2013
Export Citation:
Assignee:
CANON KK
International Classes:
G02B1/11; G02B3/00; G02B13/04
Attorney, Agent or Firm:
Yukio Takanashi