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US 12,405,462 B2Granted
Optical system and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorAkira Mizuma
Life of this patent
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Abstract
An optical system includes an optical element having negative refractive power and disposed on at least one of an object side and an image side of an intersection of an optical axis and a pupil paraxial ray. The optical element is made of a glass material and satisfies a predetermined condition.
Claims12
An optical system comprising an optical element having negative refractive power and disposed on at least one of an object side and an image side of an intersection of an optical axis and a pupil paraxial ray,
- wherein the optical element is made of a glass material, and
- wherein the following inequalities are satisfied:
- 1.70<Nd<1.85
- 28.0<νd<39.0
- −0.0100<θgF−(0.64168−0.00162×νd)<−0.0040,
- where Nd is a refractive index of the optical element for d-line, νd is an Abbe number of the optical element based on the d-line, and θgF is anomalous partial dispersion of the optical element for g-line and F-line.
3 more elements
An image pickup apparatus comprising:
- an optical system;
- and
- an image sensor configured to receive an image formed by the optical system,
- wherein the optical system includes an optical element having negative refractive power and disposed on at least one of an object side and an image side of an intersection of an optical axis and a pupil paraxial ray,
- wherein the optical element is made of a glass material, and
- wherein the following inequalities are satisfied:
- 1.70<Nd<1.85
- 28.0<νd<39.0
- −0.0100<θgF−(0.64168−0.00162×νd)<−0.0040.
- where Nd is a refractive index of the optical element for d-line, νd is an Abbe number of the optical element based on the d-line, and θgF is anomalous partial dispersion of the optical element for g-line and F-line.
7 more elements
Dependencies are inferred from the claim text.