THREE-ELEMENT TELEPHOTO LENS Russian patent published in 2006 - IPC G02B13/02 G02B9/12 G02B13/14 

FIELD: optical instrument engineering, applicable in various optical systems.

SUBSTANCE: the three-element telephoto lens has two components, the first of which is a positive one and consists of two similar menisci turned by the convexity to the object, the second component is a biconcave lens with radii similar in modulus. The relations between the value of the second air gap, focal length of the objective lens and the indices of refraction and the dispersion factors for the line from the second and third lenses are realized in the telephoto lens.

EFFECT: enhanced focal length, reduced length and enhanced adaptability to manufacture at a high quality of image for the point of the axis.

1 dwg