Patent ID: 7965450

Claim:
A microscope objective comprising at least five lens components, which are divided into three groups that are, in order from an object side: a front group having a positive refracting power as a whole and having a meniscus lens component with an object-side surface thereof being concave toward the object side; a middle group having a positive refracting power as a whole and having a plurality of cemented lens components; and a rear group having a pair of concave air-contact surfaces arranged adjacent and opposite to one another, wherein the following conditions are satisfied: 3 ≦D 0 /f≦ 6 1 ≦H 2 /H 1 ≦1.5 where D 0 is a distance, in millimeters, measured along on an optical axis, from an object surface to a rearmost surface of the microscope objective where a direction from the object side toward an image side is defined to be positive and the object surface is defined as a surface in which an observation object lies and which is perpendicular to the optical axis, f is a focal length of the microscope objective, H 2 is a height of a marginal ray as emergent from the rearmost surface of the microscope objective, and H 1 is a maximum height of the marginal ray as passing through the front group and the middle group.