INFRARED OBJECTIVE WITH SMOOTHLY CHANGING FOCAL DISTANCE Russian patent published in 2007 - IPC G02B15/16 G02B13/14 

FIELD: the invention refers to optical devices.

SUBSTANCE: the objective has in-series located the immovable first component in the shape of a positive convex-concave lens, the second movable component in the shape of a negative concave-concave lens, the movable third component in the shape of a negative concave-convex lens, the immovable the fourth component in the shape of a positive concave-convex lens and the fifth component consisting of the first positive convex-concave lens, the second negative convex-concave lens , the third negative lens, the fourth lens and the fifth positive lens, in the fifth component the third lens is fulfilled concave-concave, the fourth - negative convex-concave and the fifth - convex-convex. At that the first surfaces of the third and the fifth lenses of the fifth component are fulfilled aspherical.

EFFECT: reduces the length of the infrared objective relatively to its maximum focal distance at preserving relation of the maximal focal distance to minimal and also increases concentration of energy in the given circle of scattering.

4 cl, 1 dwg