Large aperture photographic lens system
AssigneeOlympus Optical Co., Ltd.
InventorJihei Nakagawa
Life of this patent
Estimating the term…
Abstract
A large aperture photographic lens system comprising six components of seven lenses wherein flare due to coma at intermediate field angles has been eliminated by so adapting as to satisfy the following conditions: (1) 0.9 < r.sub.11 /r.sub.9 < 1.05 , r.sub.9 > 0.55f (2) 0.95 < d.sub.8 /d.sub.10 < 1.25 (3) 1 < r.sub.5 /r.sub.4 < 1.3 (4) 0.03f < d.sub.4 < 0.05f (5) n.sub.1, n.sub.2, n.sub.5, n.sub.6, n.sub.7 > 1.75
Claims4
A large aperture photographic lens system comprising a first positive meniscus lens, a second positive meniscus lens, a third negative meniscus lens, a fourth cemented doublet lens component consisting of a negative lens and a positive lens, a fifth positive meniscus lens and sixth positive lens, and said large aperture photographic lens system satisfying the following conditions:
- (1) 0.9 <
- r.sub.11 /r.sub.9 <
- 1.05 , .vertline.r.sub. 9 .vertline. >
- 0.55f (2) 0.95 <
- d.sub.8 /d.sub.10 <
- 1.25 (3) 1 <
- r.sub.5 /r.sub.4 <
- 1.3 (4) 0.03f <
- d.sub.4 <
- 0.05f (5) n.sub.1, n.sub.2, n.sub.5, n.sub.6, n.sub.7 >
- 1.75
- wherein reference symbol f represents the focal length of the entire lens system, reference symbols r.sub.4, r.sub.5, r.sub.9 and r.sub.11 represent respective radii of curvature of the image side surface of said second lens, the object side surface of said third lens, the image side surface of said fourth component and the image side surface of said fifth lens, reference symbol d.sub.4 represents the air space between the second lens and the third lens, reference symbols d.sub.8 and d.sub.10 represent respective thicknesses of the image side lens of said fourth component and the fifth lens and reference symbols n.sub.1, n.sub.2, n.sub.5, n.sub.6 and n.sub.7 represent respective refractive indices of said first lens, said second lens, the image side lens of said fourth component, said fifth lens and said sixth lens.
A large aperture photographic lens system comprising a first positive meniscus lens, a second positive meniscus lens, a third negative meniscus lens, a fourth cemented doublet lens component consisting of a negative lens and a positive lens, a fifth positive meniscus lens and sixth positive lens, and said large aperture photographic lens system having the following numerical data:
- f = 1.0 , f.sub.B = 0.7066 , F/1.2 r.sub.1 = 0.8731 d.sub.1 = 1.034 n.sub.1 = 1.8061 .nu..sub.1 = 40.9 r.sub.2 = 3.5977 d.sub.2 = 0.0023 r.sub.3 = 0.4580 d.sub.3 = 0.0982 n.sub.2 = 1.8061 .nu..sub.2 = 40.9 r.sub.4 = 0.7210 d.sub.4 = 0.0454 r.sub.5 = 0.8444 d.sub.5 = 0.0268 n.sub.3 = 1.7847 .nu..sub.3 = 26.2 r.sub.6 = 0.3054 d.sub.6 = 0.3200 r.sub.7 = -0.3510 d.sub.7 = 0.0268 n.sub.4 = 1.78472 .nu..sub.4 = 25.7 r.sub.8 = 3.2095 d.sub.8 = 0.1327 n.sub.5 = 1.79952 .nu..sub.5 = 42.2 r.sub.9 = -0.6036 d.sub.9 = 0.0018 r.sub.10 = -2.3687 d.sub.10 = 0.1107 n.sub.6 = 1.79952 .nu..sub.6 = 42.2 r.sub.11 = -0.6074 d.sub.11 = 0.0023 r.sub.12 = 1.9981 d.sub.12 = 0.0504 n.sub.7 = 1.7859 .nu..sub.7 = 44.2 r.sub.13 = -5.2395
- wherein reference symbols r.sub.1 through r.sub.13 represent radii of curvature of respective lens surfaces, d.sub.1 through d.sub.12 denote thicknesses of respective lenses and distances between respective lenses, n.sub.1 through n.sub.7 indicate refractive indices of the lenses and .nu..sub.1 through .nu..sub.7 designate Abbe's number.
A large aperture photographic lens system comprising a first positive meniscus lens, a second positive meniscus lens, a third negative meniscus lens, a fourth cemented doublet lens component consisting of a negative lens and a positive lens, a fifth positive meniscus lens and sixth positive lens, and said large aperture photographic lens system having the following numerical data:
- f = 1 , f.sub.B = 0.6910 , F/1.2 r.sub.1 = 0.8135 d.sub.1 = 0.0887 n.sub.1 = 1.8061 .nu..sub.1 = 40.9 r.sub.2 = 2.8782 d.sub.2 = 0.0023 r.sub.3 = 0.4419 d.sub.3 = 0.1071 n.sub.2 = 1.8061 .nu..sub.2 = 40.9 r.sub.4 = 0.6246 d.sub.4 = 0.0339 r.sub.5 = 0.6965 d.sub.5 = 0.0268 n.sub.3 = 1.78472 .nu..sub.3 = 25.7 r.sub.6 = 0.2948 d.sub.6 = 0.3262 r.sub.7 = -0.3460 d.sub.7 = 0.0268 n.sub.4 = 1.78472 .nu..sub.4 = 25.7 r.sub.8 = 2.6761 d.sub.8 = 0.1178 n.sub.5 = 1.8061 .nu..sub.5 = 40.9 r.sub.9 = -0.6001 d.sub.9 = 0.0018 r.sub.10 = -1.6420 d.sub.10 = 0.1184 n.sub.6 = 1.7859 .nu..sub.6 = 44.2 r.sub.11 = -0.5630 d.sub.11 = 0.0023 r.sub.12 = 1.7856 d.sub.12 = 0.0513 n.sub.7 = 1.79952 .nu..sub.7 = 42.2 r.sub.13 = -5.3612
- wherein reference symbols r.sub.1 through r.sub.13 represent radii of curvature of respective lens surfaces, d.sub.1 through d.sub.12 denote thicknesses of respective lenses and distances between respective lenses, n.sub.1 through n.sub.7 indicate refractive indices of the lenses and .nu..sub.1 through .nu..sub.7 designate Abbe's number.
A large aperture photographic lens system comprising a first positive meniscus lens, a second positive meniscus lens, a third negative meniscus lens, a fourth cemented doublet lens component consisting of a negative lens and a positive lens, a fifth positive meniscus lens and sixth positive lens, and said large aperture photographic lens system having the following numerical data:
- f = 1 , f.sub.B = 0.6912 , F/1.2 r.sub.1 = 0.8267 d.sub.1 = 0.0888 n.sub.1 = 1.8061 .nu..sub.1 = 40.9 r.sub.2 = 3.4012 d.sub.2 = 0.0023 r.sub.3 = 0.4529 d.sub.3 = 0.1072 n.sub.2 = 1.8061 .nu..sub.2 = 40.9 r.sub.4 = 0.7059 d.sub.4 = 0.0341 r.sub.5 = 0.8472 d.sub.5 = 0.0268 n.sub.3 = 1.78472 .nu..sub.3 = 25.7 r.sub.6 = 0.3014 d.sub.6 = 0.3211 r.sub.7 = -0.3541 d.sub.7 = 0.0268 n.sub.4 = 1.78472 .nu..sub.4 = 25.7 r.sub.8 = 6.4741 d.sub.8 = 0.1179 n.sub.5 = 1.8061 .nu..sub.5 = 40.9 r.sub.9 = -0.6131 d.sub.9 = 0.0019 r.sub.10 = -1.7444 d.sub.10 = 0.1184 n.sub.6 = 1.7859 .nu..sub.6 = 44.2 r.sub.11 = -0.5707 d.sub.11 = 0.0023 r.sub.12 = 1.8066 d.sub.12 = 0.0513 n.sub.7 = 1.79952 .nu..sub.7 = 42.2 r.sub.13 = -5.3646
- wherein reference symbols r.sub.1 through r.sub.13 represent radii of curvature of respective lens surfaces, d.sub.1 through d.sub.12 denote thicknesses of respective lenses and distances between respective lenses, n.sub.1 through n.sub.7 indicate refractive indices of the lenses and .nu..sub.1 through .nu..sub.7 designate Abbe's number.
Dependencies are inferred from the claim text.