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:
Oct. 27, 1998
Filed:
Sep. 16, 1997
Kazuaki Takahashi, Omiya, JP;
Yuichi Torii, Omiya, JP;
Fuji Photo Optical Co., Ltd., Omiya, JP;
Abstract
An optical system for electronic endoscopes which makes it possible to thin tips of endoscopes and minimize illumination ununiformities. In this optical system, a prism having a half transmissive mirror film formed thereon is disposed on a rear side of an objective optical system, a CCD is optically connected to a reflecting optical path in which rays are flexed at a right angle and a light guide is connected to a straight travelling optical path. A light diffusing plate and a condenser lens are arranged between the light guide and the prism. This arrangement makes it possible to dispose the objective optical system in series with the light guide in a tip of endoscope, thereby enabling to thin the tip. Further, the diffusing plate prevents an image of a shape of an end surface of an optical fiber bundle from being projected reversely to an image pickup device. Furthermore, insufficient amount of rays in an outer circumferential portion can be corrected and uniform illumination can be obtained by arranging optical fibers at a higher density in an outer circumferential portion of the light guide.