OBJECTIVE WITH TELECENTRIC RAY PATH Russian patent published in 2007 - IPC G02B13/22 G02B9/64 

FIELD: optics.

SUBSTANCE: objective has five lens groups. Objective is provided with additional lens group, which has front focus brought into coincidence with plane of images of objective. Φv₁=φv, where Φv₁ is focal power of additional lens group, v is magnification of five lens groups and φ is focal power of whole objective. First four lens groups form first projection component (PC). Fifth lens group forms second projection component (PC₂). Magnifications VPC and VPC2 of the components meet condition of V_PC=V_PC2=(0,9+2,1). First lens group is made of two lenses; first lens is aplanatic meniscus: 0,6≤φ₁/φ≤0,7. Second and fourth lens groups have same focal powers φ_II/φ=φ_IV/φ=-0,45+-0,55. Second lens group is made in form of biconcave single lens; fourth lens group is made in form of biconcave glued lens. Third lens group is made of four positive lenses; second and third lenses of group are biconvex, and first and second lenses are menisci mounted to have their convex sides oriented in direction of biconvex lenses. Focal power of third lens group meets condition of 0,75≤φ_II/φ≤0,8. Fifth lens group is made of three lenses; first two lenses of the group have to be negative menisci mounted to have their concave sides to meet each other and third lens has to be positive meniscus. Exit pupil is removed for distance being equal at least two focal lengths of objective; front section is increased up to focal length value and "tube-infinity" condition is provided.

EFFECT: widened functional abilities.

1 dwg, 1 att