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:
Sep. 28, 1999
Filed:
Jan. 20, 1998
Yasuo Yonezawa, Zushi, JP;
Nikon Corporation, Tokyo, JP;
Abstract
The present invention provides a relay variable power optical system in a simple structure which is capable of suppressing a change of the position of the exit pupil on varying the power. To this end, the relay variable power optical system is provided with a front lens group G0 for condensing a light from a primary image, a variable power lens system (G1 to G3) for receiving the light from the front lens group G0, and performing zooming and a rear lens group G4 for forming the secondary image by condensing the light from the variable power lens system. When the zooming is performed from the high magnification end to the low magnification end, a distance between the first lens group G1 and the second lens group G2 and a distance between the second lens group G2 and the third lens group G3 are changed. The the second lens group G2 satisfies predetermined magnification conditions with respect to an axial ray from an axial object point of the primary image imaged on the secondary image and a chief ray from a position of an entrance pupil of the relay variable power optical system imaged at a position of the exit pupil.