RAPID EYEPIECE WITH REMOVABLE EXIT PUPIL Russian patent published in 2019 - IPC G02B25/00 

FIELD: optics.

SUBSTANCE: eyepiece can be used in observation devices, mainly in optical sights. Eyepiece contains three components. First component of the exit pupil is a biconvex lens, the second component is glued together from a biconvex lens and a negative meniscus facing the exit pupil with a concave surface, and the third component is a single negative lens. Following ratios are met: 1.72<n₁<1.80; 1.65<n₂<1.80; 1.75<n₃<1.82; 1.57<n₄<1.63; where n₁, n₂, n₃, n₄ - the refractive indices of the material, respectively, of the first component, the biconvex lens of the second component, the negative meniscus of the second component and the third component; f'₃=(1.8÷2.5) | f' |, where f'₃ - focal length of the third component, f' - focal length of the eyepiece. When the distance between the second and third components is not less than 0.18 of the focal length of the eyepiece, the first and second components can be made with the possibility of joint movement along the optical axis.

EFFECT: technical result is improved image quality, increased removal of the exit pupil and the relative aperture.

3 cl, 2 tbl, 5 dwg