04856495 is referenced by 42 patents and cites 3 patents.

A first optical adapter is to be detachably mounted on the distal end of an endoscope having an observation optical system and an illumination optical system, in which an aperture diaphragm which has been disposed at a given position within the observation optical system of the endoscope in the past, is disposed instead within an observaiton optical system of the optical adapter such that its optical axis is in agreement with that of the observation optical system for the endoscope. The optical adapter is selected from a set of adapters having different F numbers or the optical adapter is provided with a set of different F number diaphragms which are interchangeable. This enables the F number of the observation optical system of the endoscope apparatus to be changed by merely selecting the appropriate front optical adapter or diaphragm, depending upon brightness of the observation optical system, depth of field and brightness of an object being observed, as well as observation range and view angle of the observation optical system and the like, in order to obtain a clear observation image with optimum brightness.

Title
Endoscope apparatus
Application Number
83712
Publication Number
4856495
Application Date
October 27, 1988
Publication Date
August 15, 1989
Inventor
Tomoaki Sato
Higashiyamato
JP
Akira Hasegawa
Hachioji
JP
Yoshikazu Tohjoh
Hachioji
JP
Agent
Ostrolenk Faber Gerb & Soffen
Assignee
Olympus Optical
JP
IPC
A61B 1/06
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