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US 9,804,359 B2Granted
Imaging lens
AssigneesOptical Logic Inc., Kantatsu Co., Ltd.
InventorsYoji Kubota, Kenichi Kubota, Hitoshi Hirano, Hisao Fukaya
Life of this patent
Estimating the term…
Abstract
An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having negative refractive power; a fourth lens; a fifth lens; and a sixth lens having negative refractive power, arranged in this order from an object side to an image plane side. The fourth lens and the fifth lens have a composite focal length f45, and the third lens has an Abbe's number νd3 so that the following conditional expressions are satisfied: 0<f45, 40<νd3<75.
Claims15
An imaging lens comprising:
- a first lens having positive refractive power;
- a second lens having negative refractive power;
- a third lens having negative refractive power;
- a fourth lens;
- a fifth lens formed of one single lens and having positive refractive power;
- and
- a sixth lens formed of one single lens and having negative refractive power, arranged in this order from an object side to an image plane side with a space in between,
- wherein said second lens is formed in a shape so that a surface thereof on the object side and a surface thereof on the image plane side have positive curvature radii,
- said third lens is formed in a shape so that a surface thereof on the object side and a surface thereof on the image plane side have positive curvature radii,
- said fifth lens is formed in a shape so that a surface thereof on the image plane side has a positive curvature radius,
- said sixth lens is formed in a shape so that a surface thereof on the object side has a positive curvature radius,
- said fourth lens and said fifth lens have a composite focal length f45, and said third lens has an Abbe's number νd3 so that the following conditional expressions are satisfied:
- 0<f45,
- 40<νd3<75.
11 more elements
An imaging lens comprising:
- a first lens having positive refractive power;
- a second lens having negative refractive power;
- a third lens having negative refractive power;
- a fourth lens;
- a fifth lens formed of one single lens;
- and
- a sixth lens formed of one single lens and having negative refractive power, arranged in this order from an object side to an image plane side with a space in between,
- wherein said first lens is formed in a shape so that a surface thereof on the object side and a surface thereof on the image plane side have positive curvature radii,
- said second lens is formed in a shape so that a surface thereof on the object side has a positive curvature radius,
- said third lens is formed in a shape so that a surface thereof on the object side has a positive curvature radius,
- said fourth lens is formed in a shape so that a surface thereof on the object side has a positive curvature radius and a surface thereof on the image plane side has a negative curvature radius,
- said sixth lens is formed in a shape so that a surface thereof on the object side has a negative curvature radius, and
- said fourth lens is disposed away from the fifth lens by a distance D45 on an optical axis thereof so that the following conditional expression is satisfied:
- 0.08≦D45/f<0.2
- where f is a focal length of a whole lens system.
12 more elements
Dependencies are inferred from the claim text.