PURPOSE: To make a wide angle eyepiece system have a minimal number of lenses and have a wide angle of view and have well compensated astigmatic aberration. ;CONSTITUTION: The wide angle eyepiece system is composed of three-group four lenses, in order from an eye-point E. P to an objective lens, a lens group L1 having a positive power composed of an aspherical surface and a spherical surface, a lens group L2 having a positive power composed of the combined lens of a meniscus lens and a bi-convex lens, a lens group L3 having a positive power composed of a meniscus lens are arranged. R1 and R2 are the radii of curvature of the lens group L1 in order from the position close to the eye point E. P, R3-$5 are the radii of curvature of the lens group L2 in order from the position close to the eye point E. P and R6, R7 are the radii of curvature of the lens group L3 in order from the position close to the eye point E. P.;COPYRIGHT: (C)1995,JPO
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