Compact camera lens system with a short overall length

Claim 2

A compact camera lens system with a short overall length comprising a first positive meniscus lens component having the convex surface on the object side, a second biconcave lens component, a third biconvex lens component and a fourth negative meniscus lens component, said lens system satisfying the following conditions (1) through (9) when the focal length of the entire system is represented by f, the composite focal length from said first lens component to said third lens component is represented by f 123 , the focal length of said fourth lens component is represented by f 4 , the radius of curvature of the surface on the object side of said second lens component is represented by r 3 , the axial thicknesses of said third and fourth lens component are respectively represented by d 5 and d 7 , the airspaces between said first and second lens component is represented by d 2 , the airspace between said third and fourth lens components is represented by d 6 , the refractive index of said first lens component is represented by n 1 and the Abbe's number of said third lens component is represented by ν 3 , and further both surfaces of said fourth lens component being formed as an aspherical surface expressed by the following formula (10) when the direction of the optical axis is represented by x axis, the direction perpendicular to the optical axis is represented by y axis and the para-axial radii of curvature of both surfaces of said fourth lens component are respectively represented by r 7 and r 8 : ##EQU2## wherein reference symbols A i , B i , C i and D i (i=7, 8) respectively represent coefficients in the above formula and are of the following values respectively: A.sub.7 >-10.sup.2 f.sup.-3, B.sub.7 >-10.sup.3 f.sup.-5, C.sub.7 >-10.sup.4 f.sup.-7, D.sub.7 >-10.sup.7 f.sup.-9 A.sub.8 <-10.sup.-1 f.sup.-3, B.sub.8 <10.sup.2 f.sup.-5, C.sub.8 <-10.sup.2 f.sup.-7, D.sub.8 >10.sup.6 f.sup.9.

Claim 3

A compact camera lens system according to claim 1 having the following numerical data: ______________________________________ f = 100 2ω = 63° F-number = 4.0 r.sub.1 = 25.9559 d.sub.1 = 8.2856 n.sub.1 = 1.67790 ν.sub.1 = 55.33 r.sub.2 = 81.9207 d.sub.2 = 2.2857 r.sub.3 = -159.8784 d.sub.3 = 6.0441 n.sub.2 = 1.84666 ν.sub.2 = 23.88 r.sub.4 = 49.6331 d.sub.4 = 2.5089 r.sub.5 = 63.9734 d.sub.5 = 11.3703 n.sub.3 = 1.69895 ν.sub.3 = 30.12 r.sub.6 = -74.5690 d.sub.6 = 14.7902 r.sub.7 = -18.8537 d.sub.7 = 5.8039 n.sub.4 = 1.53172 ν.sub.4 = 48.90 r.sub.8 = -35.4535 A.sub.7 = -0.14307 × 10.sup.-4 A.sub.8 = -0.89153 × 10.sup.-5 B.sub.7 = -0.26326 × 10.sup.-7 B.sub.8 = +0.26030 × 10.sup.-8 C.sub.7 = -0.31235 × 10.sup.-10 C.sub.8 = -0.42677 × 10.sup.-10 D.sub.7 = -0.13391 × 10.sup.-11 D.sub.8 = +0.21422 × 10.sup.-13 f.sub.123 = 61.0 f.sub.4 = -86.2 Telephoto Ratio = 0.969 ______________________________________ wherein reference symbols r 1 through r 8 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 7 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 4 respectively represent refractive indices of respective lenses, reference symbols ν 1 through ν 4 respectively represent Abbe's numbers of respective lenses, reference symbols A 7 , A 8 , B 7 , B 8 , C 7 , C 8 , D 7 and D 8 respectively represent coefficients in the formula (10) of claim 1, reference symbol f 123 represents the composite focal length from said first lens component to said third lens component, and reference symbol f 4 represents the focal length of said fourth lens component.

Claim 4

A compact camera lens system according to claim 1 having the following numerical data: ______________________________________ f = 100 2ω = 63° F-number = 4.0 r.sub.1 = 26.1846 d.sub.1 = 9.9946 n.sub.1 = 1.65830 ν.sub.1 = 57.33 r.sub.2 = 73.2040 d.sub.2 = 2.8371 r.sub.3 = -153.5466 d.sub.3 = 3.1983 n.sub.2 = 1.80518 ν.sub.2 = 25.43 r.sub.4 = 62.2243 d.sub.4 = 3.8006 r.sub.5 = 62.2966 d.sub.5 = 8.5829 n.sub.3 = 1.58144 ν.sub.3 = 40.75 r.sub.6 = -77.7617 d.sub.6 = 15.8400 r.sub.7 = -15.1909 d.sub.7 = 6.3074 n.sub.4 = 1.49109 ν.sub.4 = 57.00 r.sub.8 = -24.4789 A.sub.7 = -0.61436 × 10.sup.-6 A.sub.8 = -0.26880 × 10.sup.-5 B.sub.7 = -0.19539 × 10.sup.-7 B.sub.8 = -0.46125 × 10.sup.-8 C.sub.7 = -0.32520 × 10.sup.-10 C.sub.8 = -0.30442 × 10.sup.-10 D.sub.7 = -0.25506 × 10.sup.-11 D.sub.8 = -0.11168 × 10.sup.-12 f.sub.123 = 63.7 f.sub.4 = -105.0 Telephoto Ratio = 0.959 ______________________________________ wherein reference symbols r 1 through r 8 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 7 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 4 respectively represent refractive indices of respective lenses, reference symbols ν 1 through ν 4 respectively represent Abbe's numbers of respective lenses, reference symbols A 7 , A 8 , B 7 , B 8 , C 7 , C 8 , D 7 and D 8 respectively represent coefficients in the formula (10) of claim 1, reference symbol f 123 represents the composite focal length from said first lens component to said third lens component, and reference symbol f 4 represents the focal length of said fourth lens component.

Claim 5

A compact camera lens system according to claim 1 having the following numerical data: ______________________________________ f = 100 2ω = 63° F-number = 4.0 r.sub.1 = 26.9059 d.sub.1 = 9.7438 n.sub.1 = 1.69680 ν.sub.1 = 55.52 r.sub.2 = 64.3274 d.sub.2 = 2.3711 r.sub.3 = -189.4474 d.sub.3 = 4.4269 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 54.8003 d.sub.4 = 3.6036 r.sub.5 = 54.0337 d.sub.5 = 9.9157 n.sub.3 = 1.62606 ν.sub.3 = 39.21 r.sub.6 = -94.7006 d.sub.6 = 15.4043 r.sub.7 = -16.7465 d.sub.7 = 7.5505 n.sub.4 = 1.51118 ν.sub.4 = 51.02 r.sub.8 = -27.7948 A.sub.7 = -0.53641 × 10.sup.-5 A.sub.8 = -0.41879 × 10.sup.-5 B.sub.7 = -0.25468 × 10.sup.-7 B.sub.8 = +0.18786 × 10.sup.-8 C.sub.7 = -0.31215 × 10.sup.-10 C.sub.8 = -0.42650 × 10.sup.-10 D.sub.7 = -0.13379 × 10.sup.-11 D.sub.8 = +0.21403 × 10.sup.-13 f.sub.123 = 63.5 f.sub.4 = -107.2 Telephoto Ratio = 0.982 ______________________________________ wherein reference symbols r 1 through r 8 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 7 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 4 respectively represent refractive indices of respective lenses, reference symbols ν 1 through ν 4 respectively represent Abbe's numbers of respective lenses, reference symbols A 7 , A 8 , B 7 , B 8 , C 7 , C 8 , D 7 and D 8 respectively represent coefficients in the formula (10) of claim 1, reference symbol f 123 represents the composite focal length from said first lens component to said third lens component, and reference symbol f 4 represents the focal length of said fourth lens component.

Claim 6

A compact camera lens system according to claim 1 having the following numerical data: ______________________________________ f = 100 2ω = 63° F-number = 4.0 r.sub.1 = 26.3631 d.sub.1 = 9.7398 n.sub.1 = 1.65160 ν.sub.1 = 58.67 r.sub.2 = 81.9057 d.sub.2 = 2.3707 r.sub.3 = -126.4174 d.sub.3 = 3.4846 n.sub.2 = 1.80518 ν.sub.2 = 25.43 r.sub.4 = 57.8647 d.sub.4 = 3.7417 r.sub.5 = 60.7666 d.sub.5 = 8.9686 n.sub.2 = 1.62588 ν.sub.3 = 35.70 r.sub.6 = -70.0294 d.sub.6 = 15.9378 r.sub.7 = -16.8261 d.sub.7 = 7.5976 n.sub.4 = 1.49109 ν.sub.4 = 57.00 r.sub.8 = -30.5190 A.sub.7 = -0.17484 × 10.sup.-5 A.sub.8 = -0.24260 × 10.sup.-5 B.sub.7 = -0.26455 × 10.sup.-7 B.sub.8 = +0.91479 × 10.sup.-9 C.sub.7 = -0.31306 × 10.sup.-10 C.sub.8 = -0.42802 × 10.sup.-10 D.sub.7 = -0.13429 × 10.sup.-11 D.sub.8 = +0.21483 × 10.sup.-13 f.sub.123 = 61.3 f.sub.4 = -93.4 Telephoto Ratio = 0.971 ______________________________________ wherein reference symbols r 1 through r 8 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 7 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 4 respectively represent refractive indices of respective lenses, reference symbols ν 1 through ν 4 respectively represent Abbe's numbers of respective lenses, reference symbols A 7 , A 8 , B 7 , B 8 , C 7 , C 8 , D 7 and D 8 respectively represent coefficients in the formula (10) of claim 1, reference symbol f 123 represents the composite focal length from said first lens component to said third lens component, and reference symbol f 4 represents the focal length of said fourth lens component.

Claim 7

A compact camera lens system according to claim 1 having the following numerical data: ______________________________________ f = 100 2ω = 63° F-number = 4.0 r.sub.1 = 27.1306 d.sub.1 = 8.5401 n.sub.1 = 1.72916 ν.sub.1 = 54.68 r.sub.2 = 61.0890 d.sub.2 = 2.2857 r.sub.3 = -253.2396 d.sub.3 = 6.4866 n.sub.2 = 1.84666 ν.sub.2 = 23.88 r.sub.4 = 54.3144 d.sub.4 = 3.2002 r.sub.5 = 54.1881 d.sub.5 = 11.8266 n.sub.3 = 1.66680 ν.sub.3 = 33.04 r.sub.6 = -110.1360 d.sub.6 = 15.0908 r.sub.7 = -19.2806 d.sub.7 = 4.6697 n.sub.4 = 1.53256 ν.sub.4 = 45.91 r.sub.8 = -32.4575 A.sub.7 = -0.24230 × 10.sup.-4 A.sub.8 = -0.15141 × 10.sup.-4 B.sub.7 = -0.26146 × 10.sup.-7 B.sub.8 = +0.22694 × 10.sup.-8 C.sub.7 = -0.31231 × 10.sup.-10 C.sub.8 = -0.42686 × 10.sup.-10 D.sub.7 = -0.13390 × 10.sup.-11 D.sub.8 = +0.21420 × 10.sup.-13 f.sub.123 = 65.2 f.sub.4 = -101.7 Telephoto Ratio = 0.979 ______________________________________ wherein reference symbols r 1 through r 8 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 7 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 4 respectively represent refractive indices of respective lenses, reference symbols ν 1 through ν 4 respectively represent Abbe's numbers of respective lenses, reference symbols A 7 , A 8 , B 7 , B 8 , C 7 , C 8 , D 7 and D 8 respectively represent coefficients in the formula (10) of claim 1, reference symbol f 123 represents the composite focal length from said first lens component to said third lens component, and reference symbol f 4 represents the focal length of said fourth lens component.

Claim 8

A compact camera lens system according to claim 1 having the following numerical data: ______________________________________ f = 100 2ω = 63° F-number = 4.0 r.sub.1 = 27.6535 d.sub.1 = 9.7427 n.sub.1 = 1.64000 ν.sub.1 = 60.09 r.sub.2 = 89.7825 d.sub.2 = 2.8571 r.sub.3 = -138.2979 d.sub.3 = 4.2433 n.sub.2 = 1.80518 ν.sub.2 = 25.43 r.sub.4 = 77.3393 d.sub.4 = 4.6803 r.sub.5 = 85.9732 d.sub.5 = 9.5377 n.sub.3 = 1.62606 ν.sub.3 = 39.21 r.sub.6 = -76.1224 d.sub.6 = 15.5705 r.sub.7 = -20.0695 d.sub.7 = 4.9491 n.sub.4 = 1.46450 ν.sub.4 = 65.94 r.sub.8 = -39.3516 A.sub.7 = -0.19531 × 10.sup.-4 A.sub.8 = -0.10729 × 10.sup.-4 B.sub.7 = -0.22893 × 10.sup.-7 B.sub.8 = -0.17182 × 10.sup.-8 C.sub.7 = -0.31238 × 10.sup.-10 C.sub.8 = -0.42631 × 10.sup.-10 D.sub.7 = -0.13391 × 10.sup.-11 D.sub.8 = +0.21423 × 10.sup.-13 f.sub.123 = 64.5 f.sub.4 = -96.0 Telephoto Ratio = 0.968 ______________________________________ wherein reference symbols r 1 through r 8 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 7 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 4 respectively represent refractive indices of respective lenses, reference symbols ν 1 through ν 4 respectively represent Abbe's numbers of respective lenses, reference symbols A 7 , A 8 , B 7 , B 8 , C 7 , C 8 , D 7 and D 8 respectively represent coefficients in the formula (10) of claim 1, reference symbol f 123 represents the composite focal length from said first lens component to said third lens component, and reference symbol f 4 represents the focal length of said fourth lens component.