ENDOSCOPE LENS Russian patent published in 2012 - IPC G02B9/34 G02B23/24 

FIELD: physics.

SUBSTANCE: lens consists of two components separated by an aperture diaphragm. The first component I with negative optical power φ₁ comprises a negative meniscus whose concave side faces the image, and a plane-convex lens with optical power φ₂. The second component II with positive optical power φ_II comprises a glued lens with optical power φ_3,4, which consists of a negative and a positive lens with optical power φ₃ and φ₄ respectively. In the second component II, in front of the glued lens, there is a biconvex lens with optical power φ₅. Optical power values of the lenses and components satisfy the following conditions: 0.35< Iφ₁/φI <0.45, 0.5 < φ_II/φ < 0.6, 0.35<φ₅<0.5, 0.15<φ₂<0.25, 0.65<|φ₃/φ₄|<0.75, 0.97 < dφ < 1.05, where φ is the optical power of the lens overall; d is the distance between the first and second lenses of component I.

EFFECT: ensuring acceptable image quality in the entire range of variation of the operating section, wider angular field of view, providing a beam path close to the telocentric path of principal beams in the image space and high illumination on the edges of the field of view.

2 cl, 1 dwg, 1 app