Afocal relay lens system

Claim 2

In a relay lens system arranged between an objective lens and an eyepiece and used for relaying an image of an object formed by said objective lens, a relay lens system is designed as an afocal lens system having a magnification level of 1X and comprises a first lens group, a second lens group and a third lens group, wherein said first lens group is a negative lens group, said second lens group is a positive lens group and said third lens group is a negative lens group, and wherein said relay lens system is located between the objective and the image position of the objective.

Claim 3

A relay lens system according to claim 1 satisfying the following relations: ##EQU14## wherein the reference symbols f 1 , f 2 and f 3 represent focal lengths of said first, second and third lens groups respectively, the reference symbols s 0 designate the distance in millimeters as measured from the rear focal point of said first lens group to said second lens group, the reference symbol ε denote displacement of image caused by said relay lens system and the reference symbol d represents distance between said first lens group and said third lens group.

Claim 4

A relay lens system according to claim 2 wherein said first lens group consists of a negative cemented doublet component, said second lens group consists of a positive cemented doublet component and a positive lens component, and said third lens group consists of a negative lens component, said relay lens system having the following numerical data: ______________________________________ r.sub.1 = -31.329 d.sub.1 = 1.5 n.sub.1 = 1.6425 ν.sub.1 = 58.37 r.sub.2 = 16.617 d.sub.2 = 3.0 n.sub.2 = 1.497 ν.sub.2 = 81.60 r.sub.3 = 240.41 d.sub.3 = 10.0 r.sub.4 = 695.54 d.sub.4 = 2.0 n.sub.3 = 1.56138 ν.sub.3 = 45.18 r.sub.5 = 48.835 d.sub.5 = 6.0 n.sub.4 = 1.48749 ν.sub.4 = 70.15 r.sub.6 = -27.401 d.sub.6 = 0.5 r.sub.7 = 25.499 d.sub.7 = 6.5 n.sub.5 = 1.5119 ν.sub.5 = 58.14 r.sub.8 = -53.219 d.sub.8 = 10.5 r.sub.9 = -24.213 d.sub.9 = 2.5 n.sub.6 = 1.56013 ν.sub.6 = 46.99 r.sub.10 = 33.222 d.sub.0 = 9, l = 60, ε = 20 Magnifica- Magnifi- tion of image 0.998 × , cation of pupil 1.001 × f.sub.1 = -31.6, f.sub.2 = 22.2, f.sub.3 = -24.6 ______________________________________ wherein the reference symbols r 1 through r 10 represent radii of curvature on the surfaces of the respective lens elements, the reference symbols d 1 through d 8 designate thicknesses of the respective lens elements and airspaces reserved therebetween, the reference symbols n 1 through n 6 denote refractive indices of the respective lens elements, the reference symbols ν 1 through ν 6 represent Abbe's numbers of the respective lens elements, the reference symbol d 0 designates distance as measured from the contact surface of the objective lens to said first lens group and the reference symbol l denotes distance as measured from the contact surface of the objective lens to the attached surface of the relay lens system.