Objective for microscope
AssigneeOlympus Corporation
InventorKenichiro ABE
Life of this patent
Estimating the term…
Abstract
An objective includes, in order from an object side, first, second, and third lens groups. The first lens group includes, in order from the object side, a first lens, a second lens, and a third lens component. When NA represents an objective numerical aperture, f represents an objective focal length, fG1 represents a first lens group focal length, r11 represents a radius of curvature of a lens surface on the object side of the first lens, r12 represents a radius of curvature of a lens surface on an image side of the first lens, and d012 represents a distance on an optical axis from a front-side focal plane of the objective to a lens surface on the image side of the first lens, the objective satisfies: 0.8≦NA<1, 1.6≦fG1/f≦6, −1.6≦r11/f≦−0.2, and −2≦r12/d012≦−0.86.
Claims20
A dry objective for a microscope, the dry objective comprising in order from an object side:
- a first lens group with positive refractive power;
- a second lens group with positive refractive power, the second lens group including a cemented lens that is configured of a lens with positive refractive power that is made of a low dispersion material and a lens with negative refractive power that is made of a high dispersion material;
- and
- a third lens group with negative refractive power,
- wherein:
- the first lens group includes in order from the object side:
- a first lens that is a single lens having a meniscus shape with a concave surface facing the object side;
- a second lens that is a single lens with positive refractive power, the single lens having a meniscus shape with a concave surface facing the object side;
- and
- a third lens component that is a single lens or cemented lens with positive refractive power,
- the dry objective is configured in a manner such that a ray height of an on-axis marginal ray becomes maximum on a boundary surface of a lens component closest to an object in the second lens group or within the lens component, and
- when NA represents a numerical aperture of the objective, f represents a focal length of the objective, fG1 represents a focal length of the first lens group, r11 represents a radius of curvature of a lens surface on the object side of the first lens, r12 represents a radius of curvature of a lens surface on an image side of the first lens, and do12 represents a distance on an optical axis from a front-side focal plane of the objective to a lens surface on the image side of the first lens, the objective satisfies the following conditional expressions:
- 0.8≦NA<1 (4)
- 1.6≦fG1/f≦6 (5)
- −1.6≦r11/f≦−0.2 (6)
- −2≦r12/do12≦−0.86 (7).
Dependencies are inferred from the claim text.