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US 10,620,401 B2Granted
Optical system and image pickup apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorsShigenobu Sugita, Yuichi Gyoda, Suguru Inoue
Life of this patent
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Abstract
An optical system includes a plurality of lenses. The distance from the object side lens surface of a lens arranged an the most object side to the image plane is longer than the focal length of the entire system. The material of a positive lens G1p arranged on the most object side among positive lenses included in the optical system, and the arrangement and material of a negative lens Gn located on the most object side among negative lenses arranged an the image side of the positive lens G1p are appropriately set.
Claims14
An optical system comprising:
- a positive lens G1p;
- and
- a negative lens Gn located on a most object side among negative lenses arranged on an image side of the positive lens G1p,
- wherein the positive lens G1p is a positive lens located on a most object side among positive lenses included in the optical system,
- wherein the optical system does not include a diffractive optical element, and
- wherein following conditional expressions are satisfied:
- LD/f<1.00,
- 0.25<Dpn/LD<0.50,
- 1.45<Nd1p<1.62,
- 30.0<νd1p<50.0,
- 0.17<Dpp/LD<0.50, and
- 0.15<f2p/f<0.60,
- where Nd1p and νd1p are respectively a refractive index and an Abbe number of a material of the positive lens G1p, Dpn is a distance on an optical axis between the positive lens G1p and the negative lens Gn, LD is a distance on the optical axis from a most object side lens surface of the optical system to an image plane, and f is a focal length of the optical system,
- where Dpp is a distance on the optical axis between a positive lens G2p located on a most object side among positive lenses arranged on the image side of the positive lens G1p and the positive lens G1p, and
- where ftp is a focal length of the positive lens G2p.
12 more elements
An image pickup apparatus comprising:
- an optical system;
- and
- an image pickup element configured to receive an image formed by the optical system,
- wherein the optical system includes a positive lens G1p, and a negative lens Gn located on a most object side among negative lenses arranged on an image side of the positive lens G1p,
- wherein the positive lens G1p is a positive lens located on a most object side among positive lenses included in the optical system,
- wherein the optical system does not include a diffractive optical element, and
- wherein following conditional expressions are satisfied:
- LD/f<1.00,
- 0.25<Dpn/LD<0.50,
- 1.45<Nd1p<1.62,
- 30.0<νd1p<50.0,
- 0.17<Dpp/LD<0.50, and
- 0.15<f2p/f<0.60,
- where Nd1p and νd1p are respectively a refractive index and an Abbe number of a material of the positive lens G1p, Dpn is a distance on an optical axis between the positive lens G1p and the negative lens Gn, LD is a distance on the optical axis from a most object side lens surface of the optical system to an image plane, and f is a focal length of the optical system,
- where Dpp is a distance on the optical axis between a positive lens G2p located on a most object side among positive lenses arranged on the image side of the positive lens G1p and the positive lens G1p, and
- where ftp is a focal length of the positive lens G2p.
13 more elements
Dependencies are inferred from the claim text.