The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 22, 1995
Filed:
Dec. 09, 1993
Yoshiharu Saito, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An apochromatic microscope objective of high NA wherein variation of aberrations, including chromatic aberration, caused by a change in the cover glass thickness, is minimized with a relatively simple arrangement. The microscope objective has a 1-st lens unit (G.sub.1) which includes a positive meniscus lens having a concave surface directed toward the object side to convert a bundle of rays from an object into a convergent bundle of rays, a 2-nd lens unit (G.sub.2) having a negative refractive power, and a 3-rd lens unit (G.sub.3) having a small refractive power. The 2-nd lens unit (G.sub.2) is movable relative to the 1-st and 3-rd lens units (G.sub.1 and G.sub.3) along the optical axis in accordance with a change in thickness of a transparent plane-parallel plate disposed between the 1-st lens unit (G.sub.1) and the object. The microscope objective satisfies conditions concerning the curvature radius of a lens surface in the 1-st lens unit (G.sub.1) that is the closest to the object side and the focal lengths of the 2-nd and 3-rd lens units (G.sub.2 and G.sub.3).