LENS Russian patent published in 2016 - IPC G02B9/64 

FIELD: optics.

SUBSTANCE: lens is designed for use in different optical systems, particularly in television and photosystems with multi-element radiation detectors. Lens has two groups of lenses - consisting of four and seven lenses. First lens on beam path is a negative meniscus, whose convex side faces object, second lens is biconvex, third and fourth lenses are negative menisci whose convex side faces object, fifth and seventh lenses are biconvex, sixth and eighth lenses are biconcave, ninth lens is biconvex, tenth lens is a negative meniscus whose convex side faces image, and eleventh lens is a positive meniscus whose convex side faces image. Between seventh and eighth lenses there is an aperture diaphragm. For least two negative menisci of first group of lenses and for at least, one positive lens of second group, following relationships are satisfied: β_M=β_L<-75·10^-7 1/K, where β_M and β_L are temperature coefficients of refraction index of material, respectively, of menisci from first group and positive lens from second group, K is Kelvin.

EFFECT: technical result is wider field of view, high aperture ratio and providing thermal non-detuning while maintaining image quality.

1 cl, 2 dwg, 2 tbl