HIGH-SPEED INFRARED LENS Russian patent published in 2014 - IPC G02B9/34 G02B11/22 G02B13/14 

FIELD: physics, optics.

SUBSTANCE: lens can be used for operation in the infrared range in thermal imaging devices. The lens has four components. The first component a single positive meniscus whose concave surface faces the image, the second component is a single meniscus whose convex side faces the image, the third component is a single meniscus and the fourth component is a single positive meniscus whose concave surface faces the image. The first and fourth components are made of germanium, while the second and third components are made of zinc selenide. The second component is positive and the third component is in form of a negative meniscus whose concave surface faces the image. Focal distances of the components satisfy the following conditions: F₁/F₀=1.2÷1.5; F₀/F₂=0÷0.05; |F₃|/F₀=1.6÷1.9; F₄/F₀=0.4÷0.6; where F₁, F₂, F₃, F₄, F₀ are focal distances of the first, second, third, fourth components and the lens, respectively.

EFFECT: high image quality of the lens with a high aperture ratio and large field of view.

3 cl, 4 dwg, 1 tbl