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:
Nov. 30, 1998
Filed:
Feb. 24, 1997
Masayuki Mizusawa, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Apochromatic-type microscope objective lenses are disclosed having a high numeral aperture number with few component lenses. The objective lenses are operable to correct any of various aberrations arising due to use of the objective lens with cover glasses having variable thickness. The objective lenses comprise a first positive lens group comprising a positive meniscus lens with a concave surface facing objectwise, a second positive lens group comprising a positive cemented lens in which the cemented surface has negative refractive power and a negative cemented lens in which the cemented surface has positive refractive power, and a third (negative) lens group comprising at least one cemented lens. The second and third lens groups are movable on the optical axis relative to the first lens group so as to facilitate correction of aberrations arising from use of cover glasses having variable thickness.