Objective lens system for microscopes

Claim 2

An objective lens system for microscopes comprising a first semispherical lens component having an embedded semispherical lens element, a second positive meniscus lens component having a concave surface on the object side, a third cemented lens component consisting of a positive element, a negative element and a positive element, a fourth cemented lens component consisting of a negative element, a positive element and a negative element, a fifth cemented meniscus lens component having a convex surface on the object side, and a sixth cemented meniscus lens component having a convex surface on the object side and arranged with a relatively wide airspace from said fifth lens component, and said lens system satisfying the following conditions: -80f<f.sub.4 <f.sub.5 <f.sub.6 <-29 (1) 13f>|f.sub.456 |>11f, f.sub.456 <0 (2) 5.5f>d.sub.16 >5f (3) ν.sub.12 =2.57,ν.sub.13 =66.8 (4) wherein the reference symbols f 4 , f 5 and f 6 represent focal lengths of the fourth, fifth and sixth lens components respectively, the reference symbol f 456 designates total focal length of the fourth, fifth and sixth lens components considered as an assembly, the reference symbol f denotes focal length of said lens system as a whole, the reference symbol d 16 represents air space formed between the fifth and sixth lens components, and the reference symbols ν 12 and ν 13 designate Abbe's numbers of the two elements of the sixth lens components.

Claim 3

An objective lens system for microscopes according to claim 1 having the following numerical data: ______________________________________ r.sub.1 = ∞ d.sub.1 = 0.4484 n.sub.1 = 1.51742 ν.sub.1 = 52.3 r.sub.2 = -0.4607 d.sub.2 = 1.7568 n.sub.2 = 1.883 ν.sub.2 = 40.8 r.sub.3 = -1.6929 d.sub.3 = 0.0123 r.sub.4 = -7.0921 d.sub.4 = 1.5971 n.sub.3 = 1.72342 ν.sub.3 = 38.0 r.sub.5 = -3.5319 d.sub.5 = 0.0307 r.sub.6 = 7.4939 d.sub.6 = 3.0160 n.sub.4 = 1.755 ν.sub.4 = 52.3 r.sub.7 = -6.6972 d.sub.7 = 0.6143 n.sub.5 = 1.74 ν.sub.5 = 31.7 r.sub.8 = 4.3550 d.sub.8 = 3.3170 n.sub.6 = 1.43389 ν.sub.6 = 95.2 r.sub.9 = -5.9386 d.sub.9 = 0.5344 r.sub.10 = 8.5190 d.sub.10 = 0.6143 n.sub.7 = 1.6134 ν.sub.7 = 43.8 r.sub.11 = 3.3477 d.sub.11 = 2.6044 n.sub.8 = 1.43389 ν.sub.8 = 95.2 r.sub.12 = -4.4238 d.sub.12 = 0.6143 n.sub.9 = 1.6134 ν.sub.9 = 43.8 r.sub.13 = -102.7113 d.sub.13 = 0.0614 r.sub.14 = 3.3200 d.sub.14 = 2.2727 n.sub.10 = 1.43389 ν.sub.10 = 95.2 r.sub.15 = -5.0522 d.sub.15 = 0.6143 n.sub.11 = 1.6134 ν.sub.11 = 43.8 r.sub.16 = 3.6272 d.sub.16 = 5.3931 r.sub.17 = 20.0448 d.sub.17 = 1.4803 n.sub.12 = 1.78472 ν.sub.12 = 25.7 r.sub.18 = -3.8974 d.sub.18 = 1.0934 n.sub.13 = 1.50378 ν.sub.13 = 66.8 r.sub.19 = 3.1388 f = 1.0 , β = 100X , N.A = 1.37 ΣP = 0.06 , f.sub.4 = -79.889 , f.sub.5 = -40.057 f.sub.6 = -29.682 , f.sub.456 = -12.380 ______________________________________ wherein the reference symbols r 1 through r 19 represent radii of curvature on the surfaces of the respective lens elements, the reference symbols d 1 through d 18 designate thicknesses of the respective lens elements and airspaces therebetween, the reference symbols n 1 through n 13 denote refractive indices of the respective lens elements, the reference symbols ν 1 through ν 13 represent Abbe's numbers of the respective lens elements, the reference symbols f designates focal length of the lens system as a whole, the reference symbol β denotes magnification of the lens system as a whole, the reference symbol N.A. represents numerical aperture of the lens system as a whole, the reference symbol ΣP designates Petzval's sum, the reference symbols f 4 , f 5 and f 6 denote focal lengths of the fourth, fifth and sixth lens components respectively, and the reference symbol f 456 represents total focal length of the fourth, fifth and sixth lens components considered as an assembly.

Claim 4

An objective lens system for microscopes according to claim 1 having the following numerical data: ______________________________________ r.sub.1 = ∞ d.sub.1 = 0.4348 n.sub.1 = 1.51742 ν.sub.1 = 52.3 r.sub.2 = -0.4710 d.sub.2 = 1.7271 n.sub.2 = 1.883 ν.sub.2 = 40.8 r.sub.3 = -1.6661 d.sub.3 = 0.0121 r.sub.4 = -6.7478 d.sub.4 = 1.5278 n.sub.3 = 1.72342 ν.sub.3 = 38.0 r.sub.5 = -3.4239 d.sub.5 = 0.0121 r.sub.6 = 7.4885 d.sub.6 = 2.9650 n.sub.4 = 1.755 ν.sub.4 = 52.3 r.sub.7 = -6.1582 d.sub.7 = 0.6039 n.sub.5 = 1.74 ν.sub.5 = 31.7 r.sub.8 = 4.3237 d.sub.8 = 3.2609 n.sub.6 = 1.43389 ν.sub.6 = 95.2 r.sub.9 = -5.6027 d.sub.9 = 0.4650 r.sub.10 = 8.2802 d.sub.10 = 0.06039 n.sub.7 = 1.6134 ν.sub.7 = 43.8 r.sub.11 = 3.4432 d.sub.11 = 2.5362 n.sub.8 = 1.43389 ν.sub.8 = 95.2 r.sub.12 = -3.9752 d.sub.12 = 0.6039 n.sub.9 = 1.6134 ν.sub.9 = 43.8 r.sub.13 = -204.4505 d.sub.13 = 0.0242 r.sub.14 = 3.2778 d.sub.14 = 2.2343 n.sub.10 = 1.43389 ν.sub.10 = 95.2 r.sub.15 = -4.9215 d.sub.15 = 0.6039 n.sub.11 = 1.6134 ν.sub.11 = 43.8 r.sub.16 = 3.5664 d.sub.16 = 5.0362 r.sub.17 = 17.8007 d.sub.17 = 1.4553 n.sub.12 = 1.78472 ν.sub.12 = 25.7 r.sub.18 = -3.8859 d.sub.18 = 1.0749 n.sub.13 = 1.50378 ν.sub.13 = 66.8 r.sub.19 = 3.1153 f = 1.0 , β = 100X , N.A = 1.4 ΣP = 0.074 , f.sub.4 = -63.1679 , f.sub.5 = -37.8255, f.sub.6 = -34.5278 , f.sub.456 = -11.9595 ______________________________________ wherein the reference symbols r.sub.1 through r.sub.19 represent radii of curvature on the surfaces of the respective lens elements, the reference symbols d.sub.1 through d.sub.18 designate thicknesses of the respective lens elements and airspaces therebetween, the reference symbols n.sub.1 through n.sub.13 denote refractive indices of the respective lens elements, the reference symbols ν.sub.1 through ν.sub.13 represent Abbe's numbers of the respective lens elements, the reference symbol f designates focal length of the lens system as a whole, the reference symbol β denotes magnification of the lens system as a whole, the reference symbol N.A. represents numerical aperture of the lens system as a whole, the reference symbol ΣP designates Petzval's sum, the reference symbols f.sub.4, f.sub.5 and f.sub.6 denote focal lengths of the fourth, fifth and sixth lens components respectively, and the reference symbol f.sub.456 represents total focal length of the fourth, fifth and sixth lens components considered as an assembly.