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. 17, 1999
Filed:
Oct. 31, 1997
Yutaka Suenaga, Yokohama, JP;
Masayuki Mizusawa, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Microscope objective lenses are disclosed that comprise an axially movable second lens group for correcting aberrations that arise with changes in the thickness of a cover glass or other transparent body situated between the specimen and the objective lens. An objective lens according to one aspect of the invention comprises, in order from the specimen side, first, second, third, and fourth lens groups. The first lens group is positive and comprises a negative lens cemented to a positive lens, the positive lens having a convex surface facing the specimen side. The second lens group is positive and comprises a cemented lens having a cemented surface having negative refractive power. The third lens group is positive and causes a ray bundle from the specimen, propagating divergently from the specimen, to converge toward the optical axis. The fourth lens group is negative and comprises a positive lens cemented to a negative lens, the negative lens having a concave surface facing the image side. Moving the second lens group on the optical axis allows correction of aberrations imparted by a transparent body between the specimen and the objective lens. The objective lens satisfies one or more conditional expressions.