Fixed-focal-length lens system
AssigneeFuji Photo Optical Co., Ltd.
InventorsKuniaki Ono, Masao Mori
Life of this patent
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Abstract
A fixed-focal-length lens system includes first and second lens groups arranged in order from front to rear. The first lens group consists of a plurality of lenses and has a negative refracting power and the second lens group consists of a plurality of lenses and has a positive refracting power. The fixed-focal-length lens system satisfies the following conditions 0.58<.vertline.f.sub.1 /f.vertline.<0.95 (1) 0.50<.vertline.f.sub.1 /f.sub.2 .vertline.<1.0 (2) 1.6<Bf/f<2.9 (3) 1.1<f.sub.2 /f<1.45 (4) wherein f represents the focal length of the fixed-focal-length lens system, f.sub.1 represents the focal length of the first lens group, f.sub.2 represents the focal length of the second lens group and Bf represents the back focus of the lens system.
Claims4
A fixed-focal-length lens system comprising first and second lens groups arranged in order from front to rear, the first lens group consisting of a plurality of lenses and having a negative refracting power and the second lens group consisting of a plurality of lenses and having a positive refracting power, wherein the fixed-focal-length lens system satisfies the following conditions
- 0.58<.vertline.f.sub.1 /f.vertline.<0.95 (1)
- 0.50<.vertline.f.sub.1 /f.sub.2 .vertline.<1.0 (2)
- 1.6<Bf/f<2.9 (3)
- 1.1<f.sub.2 /f<1.45 (4)
- wherein f represents the focal length of the fixed-focal-length lens system, f.sub.1 represents the focal length of the first lens group, f.sub.2 represents the focal length of the second lens group and Bf represents the back focus of the lens system.
Dependencies are inferred from the claim text.