Microscope objective lens system

Claim 2

A microscope objective lens system comprising a first positive meniscus lens component having a concave surface on the object side, a second positive cemented lens component, a third positive cemented lens component and a fourth negative meniscus lens component having a concave surface on the image side, and said lens system satisfying the following conditions: (1) 1.79<n 1 <1.81 (2) 40<ν 1 <43 (3) 1.60f<f 1 <1.63f (4) 3.5f<|f 4 |<4.5f (5) 1.24f<d 5 <1.27f wherein the reference symbol n 1 represents the refractive index of said first lens component, the reference symbol ν 1 designates the Abbe number of said first lens component, the reference symbol d 5 denotes the airspace between the second and third lens components and the reference symbols f 1 , f 4 and f represent focal lengths of said first lens component, fourth lens component and the entire lens system as a whole.

Claim 3

A microscope objective lens system according to claim 1 having the following numerical data: ______________________________________ f = 1 NA = 0.4 β = -20x WD = 0.7632 r.sub.1 = -2.5417 d.sub.1 = 0.2862 n.sub.1 = 1.79952 ν.sub.1 = 42.24 r.sub.2 = -0.9012 d.sub.2 = 0.0193 r.sub.3 = 5.3927 d.sub.3 = 0.1643 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 1.2677 d.sub.4 = 0.3722 n.sub.3 = 1.49250 ν.sub.3 = 81.90 r.sub.5 = -1.9863 d.sub.5 = 1.2436 r.sub.6 = 1.9185 d.sub.6 = 0.3645 n.sub.4 = 1.49250 ν.sub.4 = 81.90 r.sub.7 = -3.4138 d.sub.7 = 0.1938 n.sub.5 = 1.66998 ν.sub.5 = 39.32 r.sub.8 = -5.0035 d.sub.8 = 0.4620 r.sub.9 = 1.8588 d.sub.9 = 0.4030 n.sub.6 = 1.71736 ν.sub.6 = 29.51 r.sub.10 = 0.9810 f.sub.1 = 1.6209 f.sub.4 = -3.5832 ______________________________________ wherein the reference symbol f represents focal length of the entire lens system as a whole, the reference symbols r 1 through r 10 designate radii of curvature on the respective surfaces of the lens elements, the reference symbols d 1 through d 9 denote thicknesses of said elements and airspaces therebetween, the reference symbols n 1 through n 6 represent refractive indices of the respective lens elements, the reference symbols ν 1 through ν 6 designate Abbe's numbers of the respective lens elements and the reference symbols f 1 and f 4 denote focal lengths of said first and fourth lens components.

Claim 4

A microscope objective lens system according to claim 1 having the following numerical data: ______________________________________ f = 1 NA = 0.4 β = -20x WD = 0.7651 r.sub.1 = -2.5345 d.sub.1 = 0.2890 n.sub.1 = 1.8061 ν.sub.1 = 40.92 r.sub.2 = -0.9060 d.sub.2 = 0.0180 r.sub.3 = 5.4215 d.sub.3 = 0.1541 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 1.2707 d.sub.4 = 0.3610 n.sub.3 = 1.4925 ν.sub.3 = 81.90 r.sub.5 = -1.9896 d.sub.5 = 1.2653 r.sub.6 = 1.9330 d.sub.6 = 0.3648 n.sub.4 = 1.4925 ν.sub.5 = 81.90 r.sub.7 = -3.4433 d.sub.7 = 0.2351 n.sub.5 = 1.6668 ν.sub.5 = 33.04 r.sub.8 = -4.9679 d.sub.8 = 0.4586 r.sub.9 = 1.8685 d.sub.9 = 0.3995 n.sub.6 = 1.71736 ν.sub.6 = 29.51 r.sub.10 = 0.9847 f.sub.1 = 1.6211 f.sub.4 = -3.5787 ______________________________________ wherein the reference symbol f represents focal length of the entire lens system as a whole, the reference symbols r 1 through r 10 designate radii of curvature on the respective surfaces of the lens elements, the reference symbols d 1 through d 9 denote thicknesses of said elements and airspaces therebetween, the reference symbols n 1 through n 6 represent refractive indices of the respective lens elements, the reference symbols ν 1 through ν 6 designate Abbe's numbers of the respective lens elements and the reference symbols f 1 and f 4 denote focal lengths of said first and fourth lens components.

Claim 5

A microscope objective lens system according to claim 1 having the following numberical data: ______________________________________ f = 1 NA = 0.4 β = -20x WD = 0.7586 r.sub.1 = -2.4180 d.sub.1 = 0.2702 n.sub.1 = 1.79952 ν.sub.1 = 42.24 r.sub.2 = -0.8803 d.sub.2 = 0.0064 r.sub.3 = 4.4237 d.sub.3 = 0.1460 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 1.2806 d.sub.4 = 0.3548 n.sub.3 = 1.4925 ν.sub.3 = 81.90 r.sub.5 = -2.3545 d.sub.5 = 1.2590 r.sub.6 = 1.8365 d.sub.6 = 0.2382 n.sub.4 = 1.6727 ν.sub.4 = 32.10 r.sub.7 = 1.2987 d.sub.7 = 0.3663 n.sub.5 = 1.4925 ν.sub.5 = 81.90 r.sub.8 = -5.9704 d.sub.8 = 0.4585 r.sub.9 = 1.6858 d.sub.9 = 0.4047 n.sub.6 = 1.71736 ν.sub.6 = 29.51 r.sub.10 = 0.9940 f.sub.1 = 1.6061 f.sub.4 = -4.4672 ______________________________________ wherein the reference symbol f represents focal length of the entire lens system as a whole, the reference symbols r 1 through r 10 designate radii of curvature on the respective surfaces of the lens elements, the reference symbols d 1 through d 9 denote thicknesses of said elements and airspaces therebetween, the reference symbols n 1 through n 6 represent refractive indices of the respective lens elements, the reference symbols ν 1 through ν 6 designate Abbe's numbers of the respective lens elements and the reference symbols f 1 and f 4 denote focal lengths of said first and fourth lens components.