| 摘要 |
FIELD: physics.SUBSTANCE: lens comprises a first positive meniscus made of oxygen-free glass IKS-25, whose concave surface faces the image plane, a second negative meniscus made of zinc selenide, whose concave surface faces the image plane, a third negative and a fourth positive menisci made of germanium, whose concave surfaces face the image plane. The following relationships are satisfied: ?:?:?:?=(0.72-0.85):-(1.28-1.76):-(3.00-6.00):(0.79-0.92), where ?, ?, ?, ?denote relative optical power of the first, second, third and fourth menisci, respectively.EFFECT: high image contrast on the entire field of vision in a wide temperature range.2 cl, 3 dwg, 3 tbl |
