Microscope objective lens
AssigneeNikon Corporation
InventorMiwako Yoshida
Life of this patent
Estimating the term…
Abstract
A microscope objective lens includes, in order from an object side, a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, and is configured such that the first lens group includes, on the most object side, a positive meniscus lens whose concave surface is directed to the object side, such that the second lens group includes a diffractive optical element having positive refractive power, and such that the diffractive optical element is arranged at a position closer to the image than a portion at which the diameter of a light flux passing through the first lens group and the second lens group is the largest.
Claims8
A microscope objective lens comprising, in order from an object side,
- a first lens group having positive refractive power,
- a second lens group having positive refractive power, and
- a third lens group having negative refractive power, wherein
- the first lens group includes, on the most object side, a positive meniscus lens whose concave surface is directed to the object side,
- the second lens group includes a diffractive optical element having positive refractive power, and
- the microscope objective lens satisfying the following expressions:
- 0.5≤(−r1)/F≤4.2
- 2≤f1/F≤10
- 15≤f2/F≤30
- where a radius of curvature of the most object side lens surface of the first lens group is set as r1, a focal length of the whole lens system is set as F, a focal length of the first lens group is set as f1, and a focal length of the second lens group is set as f2.
Dependencies are inferred from the claim text.