Objective lens system
AssigneeOlympus Optical Co., Ltd.
InventorShingo Kashima
Life of this patent
Estimating the term…
Abstract
An objective lens system comprising at least one diffractive optical element, having a high magnification and a large numerical aperture, and capable of favorably correcting aberrations, in particular, longitudinal chromatic aberration and lateral chromatic aberration.
Claims12
An objective lens system comprising in order from the object side:
- a first lens unit including one of a plano-convex lens component having a planar surface on the object side and a meniscus lens component having a concave surface on the object side, said first lens unit has a positive refractive power as a whole;
- and
- a second lens unit including at least one diffractive optical element;
- wherein said objective lens system satisfies the following conditions (1), (2) and (4):
- (1) D.sub.1 /D>0.8
- (2) (h.times.f) / (L.times.I)>0.07
- (4) 0.5<.vertline.R/t.vertline.<5
- wherein the reference symbol D.sub.1 represents a diameter of a marginal light bundle as measured at a location on said diffractive optical element, the reference symbol D designates a maximum diameter of a marginal light bundle in said objective lens system, the reference symbol h denotes a height of a principal ray at a location on said diffractive optical element, the reference symbol f represents a focal length of said objective lens system, the reference symbol L designates a parfocality length of said objective lens system, the reference symbol I denotes a maximum image height on a specimen surface, the reference symbol R represents a radius of curvature on an image side surface of one of said plano-convex lens component and said meniscus lens component and the reference symbol t designates thickness of said one of said plano-convex lens component and said meniscus lens component.
An objective lens system comprising two diffractive optical elements and two meniscus lens components having convex surfaces opposed to each other disposed between said two diffractive optical elements and wherein said objective lens system comprises a lens component made of fused silica and a plurality of diffractive elements.
An objective lens system comprising two diffractive optical elements and two meniscus lens components having concave surfaces opposed to each other disposed between said two diffractive optical elements and wherein said objective lens system comprises a lens component made of fused silica and a plurality of diffractive elements.
An objective lens system comprising:
- two diffractive optical elements;
- and
- two meniscus lens components having convex surfaces opposed to each other disposed between said two diffractive optical elements, and
- wherein at least one of said diffractive optical elements satisfies at least one of the following conditions (1) and (2):
- (1) D.sub.i /D>0.8
- (2) (h.times.f) / (L.times.I)>0.07
- wherein the reference symbol D.sub.1 represents a diameter of a marginal light bundle as measured at a location on said diffractive optical element, the reference symbol D designates a maximum diameter of the marginal light bundle in said objective lens system, the reference symbol h denotes a height of a principle ray at the location on said diffractive optical element, the reference symbol f represents a focal length of said objective lens system, the reference symbol L designates a parfocality length of said objective lens system, and the reference symbol I denotes a maximum image height on a specimen surface.
An objective lens system comprising:
- two diffractive optical elements;
- and
- two meniscus lens components having concave surfaces opposed to each other disposed between said two diffractive optical elements, and
- wherein at least one of said lens components is made of fused silica, and at least one of said diffractive optical elements satisfies at least one of the following conditions (1) and (2):
- (1) D.sub.1 /D>0.8
- (2) (h.times.f) / (L.times.I)>0.07
- wherein the reference symbol D.sub.1 represents a diameter of a marginal light bundle as measured at a location on said diffractive optical element, the reference symbol D designates a maximum diameter of the marginal light bundle in said objective lens system, the reference symbol h denotes height of a principle ray at a location on said diffractive optical element, the reference symbol f represents a focal length of said objective lens system, the reference symbol L designates a parfocality length of said objective lens system, and the reference symbol I denotes a maximum image height on a specimen surface.
Dependencies are inferred from the claim text.