EYEPIECE WITH INCREASED EYE RELIEF OF THE EXIT PUPIL Russian patent published in 2018 - IPC G02B25/00 

FIELD: weapons and ammunition.

SUBSTANCE: invention can be used in thermal imaging sights for small arms. Eyepiece contains three components, the first of which is a negative meniscus, which is turned by a concave surface to the plane of objects, the second is a single plane-convex lens, and the third is a positive doublet consisting of a biconvex positive lens and a negative meniscus. Second surface of a single lens is made aspherical with a conical constant ranging from (-0.25) to (-0.6). Following conditions are met: ϕ₁=-(0.67÷1.17), ϕ₂=0.82÷1.08, ϕ₃=0.28÷0.47, where ϕ_1, ϕ₂, ϕ₃ – the optical power of the first, second and third components, respectively.

EFFECT: increase in the eye relief of the exit pupil, an increase in the diameter of the exit pupil and an improvement in the image quality throughout the field of view.

1 cl, 2 tbl, 3 ex