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US4303314A Expired / Lapsed US ⏱️ 0.0 years remaining

Compact telephoto lens

Assignee: Nikon Corp
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Filing: 1980-03-03
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Granted: 1981-12-01
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Expires: 2000-03-03
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Abstract

Abstract A compact telephoto lens comprises, in succession from the object side, a first lens which is a single positive lens having its surface of sharper curvature facing the object side, a second lens which is a positive meniscus lens having its convex surface facing the object side, a third lens which is a single negative lens having its surface of sharper curvature facing the image side, a stop, and a fourth lens which is a single positive lens having its surface of sharper curvature facing the object side. The telephoto lens satisfies specific conditions.

Inventors

  • 👤 Sei Matsui

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 23:27
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/02

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 269 words
A compact telephoto lens having an angle of view of 18° to 24°, an aperture ratio of 1:2.8 and a telephoto ratio of 0.92 to 0.94, and consisting essentially of, in succession from the object side, a first lens which is a single positive lens having its surface of sharper curvature facing the object side, a second lens which is a positive meniscus lens having its convex surface facing the object side, a third lens which is a single negative lens having its surface of sharper curvature facing the image side, a stop, and a fourth lens which is a single positive lens having its surface of sharper curvature facing the object side, said telephoto lens satisfying the following conditions: ______________________________________ 0.35 < f.sub.12 < 0.4f (I) 0.2f < d.sub.1 + d.sub.2 + d.sub.3 + d.sub.4 + d.sub.5 < 0.25f 0.19f < r.sub.6 < 0.21f 1.35f < f.sub.123 < 1.46f (II) 0.27f < d.sub.6 < 0.32f n.sub.1, n.sub.2 > 1.6,n.sub.3, n.sub.4 > 1.7 (III) γ.sub.1, γ.sub.2 > 50, γ.sub.3, γ.sub.4 < 30 where r 1 -r 8 represent the radii of curvature, d 1 -d 7 represent the center thickness and air spaces of the respective lenses, n 1 -n 4 represent the refractive indices of the respective lenses, γ 1 -γ 4 represent the Abbe numbers of the respective lenses, f 1-4 represent of the focal lengths of the respective lenses, f represents the total focal length of the entire system, f 123 represents the total focal length of the first to third lenses and f 12 represents the total focal length of the first and second lenses.
Claim 2
Dependent Claim 269 words
A compact telephoto lens having an angle of view of 18° to 24°, an aperture ratio of 1:2.8 and a telephoto ratio of 0.92 to 0.94, and consisting essentially of, in succession from the object side, a first lens which is a single positive lens having its surface of sharper curvature facing the object side, a second lens which is a positive meniscus lens having its convex surface facing the object side, a third lens which is a single negative lens having its surface of sharper curvature facing the image side, a stop, and a fourth lens which is a single positive lens having its surface of sharper curvature facing the object side, said telephoto lens satisfying the following conditions: ______________________________________ 0.35 < f.sub.12 < 0.4f (I) 0.2f < d.sub.1 + d.sub.2 + d.sub.3 + d.sub.4 + d.sub.5 < 0.25f 0.19f < r.sub.6 < 0.21f 1.35f < f.sub.123 < 1.46f (II) 0.27f < d.sub.6 < 0.32f n.sub.1, n.sub.2 > 1.6,n.sub.3, n.sub.4 > 1.7 (III) γ.sub.1, γ.sub.2 > 50, γ.sub.3, γ.sub.4 < 30 where r 1 -r 8 represent the radii of curvature, d 1 -d 7 represent the center thickness and air spaces of the respective lenses, n 1 -n 4 represent the refractive indices of the respective lenses, γ 1 -γ 4 represent the Abbe numbers of the respective lenses, f 1-4 represent of the focal lengths of the respective lenses, f represents the total focal length of the entire system, f 123 represents the total focal length of the first to third lenses and f 12 represents the total focal length of the first and second lenses.
Claim 3
Dependent Claim 100 words
A compact telephoto lens according to claim 1, wherein numerical data are as follows: ______________________________________ focal length f = 100 aperture ratio 1:2.8 angle of view 2ω = 24° ______________________________________ r1 = 41.0 d1 = 5.3 n1 = 1.61272 ν1 = 58.6 r2 = 298.19 d2 = 0.75 r3 = 29.92 d3 = 9.8 n2 = 1.62041 ν2 = 60.3 r4 = 71.72 d4 = 1.8 r5 = 149.221 d5 = 4.5 n3 = 1.71736 ν3 = 29.5 r6 = 19.836 d6 = 29.4 r7 = 71.0 d7 = 2.0 n4 = 1.74077 ν4 = 27.7 r8 = 227.07 ______________________________________
Claim 4
Dependent Claim 100 words
A compact telephoto lens according to claim 1, wherein numerical data are as follows: ______________________________________ focal length f = 100 aperture ratio 1:2.8 angle of view 2ω = 24° ______________________________________ r1 = 41.0 d1 = 5.0 n1 = 1.61272 ν1 = 58.6 r2 = 298.19 d2 = 0.95 r3 = 29.692 d3 = 9.5 n2 = 1.61272 ν2 = 58.6 r4 = 70.0 d4 = 2.1 r5 = 147.466 d5 = 4.8 n3 = 1.72825 ν3 = 28.3 r6 = 20.0 d6 = 27.8 r7 = 65.73 d7 = 2.5 n4 = 1.74077 ν4 = 27.7 r8 = 181.204 ______________________________________
Claim 5
Dependent Claim 100 words
A compact telephoto lens according to claim 1, wherein numerical data are as follows: ______________________________________ focal length f = 100 aperture ratio 1:2.8 angle of view 2ω = 18.1° ______________________________________ r1 = 42.593 d1 = 5.0 n1 = 1.62041 ν1 = 58.6 r2 = 374.909 d2 = 0.963 r3 = 30.0 d3 = 9.778 n2 = 1.62041 ν2 = 58.6 r4 = 72.507 d4 = 1.778 r5 = 149.507 d5 = 5.556 n3 = 1.71736 ν3 = 29.5 r6 = 19.644 d6 = 31.111 r7 = 70.963 d7 = 1.926 n4 = 1.7847 ν4 = 26.1 r8 = 187.227 ______________________________________

References Cited (Backward Citations)

US3018688A Cited
DE1268404B Cited
US3649104A Cited
US4057330A Cited
US4063802A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-11-30 1985-06-01 1985-12-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-11-30 1989-06-01 1989-12-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-11-30 1993-06-01 1993-12-01 $7700.00 Window Closed / Lapsed

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