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:
May. 24, 1994
Filed:
Sep. 13, 1993
Kenji Hori, Tokyo, JP;
Wataru Tatsuno, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An inverse telephoto large aperture wide angle lens comprises a first lens group with a negative refractive power, a second lens group with a positive refractive power, a stop, a third lens group with a negative refractive power, and a fourth lens group with a positive refractive power arranged in the named order from a side of an object, in which for focusing on a near object from infinity the first lens group is fixed with respect to an image surface, and the second, third, and fourth lens groups are moved along an optical axis thereof toward the object such that a space between the first lens group and the second group and a space between the second lens group and the third lens group decrease, but a space between the third lens group and the fourth lens group increases.