发明名称 |
Imaging lens |
摘要 |
An imaging lens includes a first lens group having negative refractive power; a stop; and a second lens group having positive refractive power, arranged in the order from the object side to the image plane side. The first lens group includes a first lens having a strong concave surface facing the image plane side and negative refractive power; and a second lens having negative refractive power and a biconcave lens shape near the optical axis. The second lens group includes a third lens having a biconvex shape; and a lens group that is composed of a lens having positive refractive power and a lens having negative refractive power, and has negative refractive power as a whole. The first lens group has a focal length F1 and the second lens group has a focal length F2 so that the following conditional expression is satisfied:
−1.0<F1/F2<−0.5. |
申请公布号 |
US9013812(B2) |
申请公布日期 |
2015.04.21 |
申请号 |
US201414181758 |
申请日期 |
2014.02.17 |
申请人 |
Optical Logic Inc. |
发明人 |
Kubota Yoji;Kubota Kenichi;Hirano Hitoshi |
分类号 |
G02B13/04;G02B9/04;G02B13/00;G02B9/34;G02B9/60 |
主分类号 |
G02B13/04 |
代理机构 |
Kubotera & Associates, LLC |
代理人 |
Kubotera & Associates, LLC |
主权项 |
1. An imaging lens comprising:
a first lens group having negative refractive power; a stop; and a second lens group having positive refractive power, arranged in the order from an object side to an image plane side, wherein said first lens group includes a first lens having a strong concave surface facing the image plane side and negative refractive power; and a second lens having negative refractive power and a shape of a biconcave lens near an optical axis thereof, said second lens group includes a third lens having a biconvex shape and a lens group, said lens group is composed of a lens having positive refractive power and a lens having negative refractive power, and has negative refractive power as a whole, said first lens group has a focal length F1 and said second lens group has a focal length F2 so that the following conditional expression is satisfied:
−1.0<F1/F2<−0.5 said first lens has a focal length f1 and said second lens has a focal length f2 so that the following conditional expression is satisfied:
0.2<f1/f2<1.5. |
地址 |
Nagano JP |