US 10,095,005 B2Granted

Imaging lens

AssigneeKantatsu Co., Ltd.

InventorsYoji Kubota, Kenichi Kubota, Hitoshi Hirano, Hisao Fukaya

Life of this patent

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Abstract

An imaging lens includes a first lens group and a second lens group, arranged from an object side to an image plane side. The first lens group includes two lenses having positive refractive power, one lens having negative refractive power and at least one aspheric surface, and an aperture stop disposed between the two positive lenses. The second lens group includes one lens having positive refractive power and at least one aspheric surface and two lenses having negative refractive power and two aspheric surfaces. The lens of the second lens group situated at a nearest position to the image plane side is formed so that a curvature radius of the surface on the object side and a curvature radius of the surface on the image plane side are negative near an optical axis thereof. The first lens group is arranged away from the second lens group by a specific distance.

Claims18

Dependent claims

An imaging lens comprising:

a first lens group;
and
a second lens group, arranged in this order from an object side to an image plane side,
wherein said first lens group includes two lenses each having positive refractive power, one lens having negative refractive power and at least one aspheric surface, and an aperture stop disposed between the two lenses having positive refractive power, said three lenses being arranged with a space in between,
said second lens group includes one lens having positive refractive power and at least one aspheric surface and two lenses each having negative refractive power and two aspheric surfaces, said three lenses being arranged with a space in between,
one of said three lenses of the second lens group situated at a nearest position to the image plane side is formed in a shape so that a curvature radius of the surface thereof on the object side and a curvature radius of the surface thereof on the image plane side are negative near an optical axis thereof, and
said first lens group is arranged away from the second lens group by a distance D34 on an optical axis thereof so that the following conditional expression is satisfied:
0.1<D34/f<0.4
where f is a focal length of a whole lens system.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/430,634Filed 13 Feb 2017 · continuation
Priority: JP 2014-1365412 Jul 2014
Published: US 2017/0153425 A11 Jun 2017
Granted: 9 Oct 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G02B 13/0045
Having at least one aspherical surface: having five or more lenses
G02B 9/62
Optical objectives characterised both by the number of the components and their arrangements according to their sign, i.e. + or -: having six…
G02B 27/0025
Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00: for optical correction, e.g. distorsion,…
G02B 5/005
Optical elements other than lenses: diaphragms

Family

Application14/568,173Parent of this continuation · filed 12 Dec 2014
Application15/131,111Parent of this continuation · filed 18 Apr 2016
US 9,341,822 B2Parent of this continuation · filed 17 May 2016
US 2017/0153425 A1Pre-grant publication · published 1 Jun 2017
US 9,846,297 B2Parent of this continuation
US 2016/0004042 A1Published application
US 2016/0231537 A1Published application
US 10,095,005 B2This patent

From the US filing history. Foreign family members aren’t listed.