Anti-reflection coating, and optical element and optical system with anti-reflection coating
AssigneeNikon Corporation
InventorsIssei Tanaka, Tsuyoshi Murata
Life of this patent
Estimating the term…
Abstract
An anti-reflection coating is formed on an optical surface of an optical member for reducing the amount of light rays reflected from the optical surface. For light rays in a wavelength range from 400 nm to 700 nm, the anti-reflection coating has a reflectance of 0.5% or less if the light rays are incident on the optical surface at angles within a range from 0 to 25 degrees, and it has a reflectance of 3.5% or less if the light rays are incident at angles within a range from above 25 degrees to 60 degrees.
Claims34
An anti-reflection coating formed on an optical surface of an optical member for reducing an amount of light rays reflected from said optical surface, wherein:
- for light rays in a wavelength range from 400 nm to 700 nm,
- said anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees.
An optical element comprising an optical member having an optical surface which is a plane or a curved surface, and an anti-reflection coating which is formed on the optical surface of said optical member for reducing an amount of light rays reflected from said optical surface, wherein:
- for light rays in a wavelength range from 400 nm to 700 nm,
- said anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees.
An optical system comprising an optical element, which is positioned between an object and an image plane, wherein:
- at least one optical surface of said optical element is provided with an anti-reflection coating;
- and
- for light rays in a wavelength range from 400 nm to 700 nm,
- said anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees.
An optical system comprising a plurality of optical surfaces, wherein:
- at least one of an n-th ghost-generating surface and an m-th ghost-generating surface of said optical surfaces is provided with an anti-reflection coating;
- and
- for light rays in a wavelength range from 400 nm to 700 nm,
- said anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees;
- and
- said optical system satisfies the following formula
- Rn×Rm≦0.10[%]
- with “Rn” representing the reflectance of said n-th ghost-generating surface and “Rm” representing the reflectance of said m-th ghost-generating surface.
A method for reducing an amount of light rays reflected from an optical surface of an optical member, the method comprising:
- forming an anti-reflection coating on said optical surface such that, for light rays in a wavelength range from 400 nm to 700 nm, the anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees.
A method for forming an optical element, comprising:
- providing an optical member having an optical surface which is a plane or a curved surface, and
- forming an anti-reflection coating on said optical surface of said optical member such that for light rays in a wavelength range from 400 nm to 700 nm, the anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees.
A method for forming an optical system, comprising:
- providing an optical element, which is positioned between an object and an image plane,
- wherein at least one optical surface of said optical element is provided with an anti-reflection coating, and
- for light rays in a wavelength range from 400 nm to 700 nm, the anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees.
A method for forming an optical system having a plurality of optical surfaces, the method comprising:
- providing at least one of an n-th ghost-generating surface and an m-th ghost-generating surface of said optical surfaces with an anti-reflection coating,
- wherein for light rays in a wavelength range from 400 nm to 700 nm, the anti-reflection coating has:
- a reflectance of 0.5% or less if said light rays are incident on said optical surface at angles within a range from 0 to 25 degrees, and
- a reflectance of 3.5% or less if said light rays are incident on said optical surface at angles within a range from above 25 degrees to 60 degrees, and
- the following formula is satisfied:
- Rn×Rm≦0.10[%]
- “Rn” representing the reflectance of said n-th ghost-generating surface, and “Rm” representing the reflectance of said m-th ghost-generating surface.
Dependencies are inferred from the claim text.