LENS UNIT FOR INFRARED REGION OF SPECTRUM Russian patent published in 2001 - IPC

FIELD: optical devices. SUBSTANCE: lens unit has two components; first component has positive lens and glued double-meniscus assembly incorporating convexo-convex and concavo- concave lenses; second component has negative meniscus whose convex side faces object and positive lens. First lens of first component is convexo-convex lens and second lens of second component is positive meniscus whose convex side faces object. EFFECT: improved quality of image due to correction of axial and beyond-axis aberrations. 2 dwg, 1 tbl