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. 16, 2005
Filed:
Jan. 20, 2004
Shinichiro Ishii, Saitama, JP;
Shinichiro Ishii, Saitama, JP;
PENTAX Corporation, Tokyo, JP;
Abstract
A vari-focal polar alignment scope includes an objective optical system, a relay optical system, and an eyepiece optical system, in that order from the object side. The relay optical system includes an erecting vari-focal viewing optical system, including a positive condenser lens element, and positive second and third relay lens groups which relatively move in the optical axis direction so as to vary the magnification of the polar alignment scope, wherein the following conditions (1), (2) and (3) are satisfied:6.0<<10.0  (1);−4.0<<−1.0  (2); and0.2<<0.6  (3); wherein fdesignates the focal length of the objective optical system; fe designates the focal length of the eyepiece optical system; Mdesignates the lateral magnification of the second lens group of the relay optical system at a low magnification; and Mdesignates the lateral magnification of the third lens group of the relay optical system at a low magnification.