INFRARED TELESCOPE WITH TWO MAGNIFICATIONS Russian patent published in 2001 - IPC

FIELD: infrared optical systems, applicable in infrared imagers. SUBSTANCE: the telescope consists of an objective comprising the first positive lens component, second negative component for the change of magnification, having two fixed positions in the optical axis in these fixed positions, third positive lens component, fourth negative lens component, and an eye-piece, they have the following relations: R₅/|R₆|≅0,5, |R₈|/R₁≥0,2, where R₅-radius of curvature of the first surface of the third lens component, R₆-radius of curvature of the second surface of the third lens component, R₈-radius of curvature of the second surface of the fourth lens component, R₁- radius of curvature of the first surface of the first lens component. EFFECT: enhanced quality of image and reduced number of telescope lenses. 5 cl, 6 dwg