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. 14, 1993
Filed:
Apr. 26, 1991
Yoshiharu Takasugi, Iruma, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An imaging optical system for endoscopes used for re-imaging an image formed by endoscopes, comprising in the order from the object side a first lens unit which has a positive refractive power and a focusing function, a second lens unit which has a negative refractive power and is moved in a definite direction along the optical axis so as to progressively enhance magnification of the imaging optical system when the optical system is zoomed from the wide position to the tele position, and a third lens unit which has a positive refractive power and is moved along the optical axis so as to keep the image point constant regardless of variation of focal length, said first lens unit being adapted as to be moved independently of the other lens units for varying diopteric power within a positive-to-negative range taking the diopter at the infinite object distance for the imaging optical system as zero.