Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
VARIABLE POWER OPTICAL SYSTEM FOR ENDOSCOPE AND ENDOSCOPE
Document Type and Number:
WIPO Patent Application WO/2019/163744
Kind Code:
A1
Abstract:
A variable power optical system for an endoscope is provided with, in order from an object, a first lens group having a negative power and a second lens group having a positive power and capable of moving along the optical axis. The first lens group includes a negative lens with the concave surface facing an image and a positive lens with the convex surface facing the object in order from the object, and the second lens group includes a cemented lens bonded to a positive lens with the convex surface facing the object. The variable power optical system for an endoscope satisfies the following expressions: 0.6 < |fs1 / f1| < 1.6, 1.2 < ft / fw < 1.4, and 0.5 < |f2 / f1| < 0.8 where f1 [mm] and f2 [mm] represent synthetic focal lengths of the first and second lens groups, respectively; fw [mm] represents a synthetic focal length for the entire system when observing a distant object; ft [mm] represents a synthetic focal length for the entire system when observing an enlarged object; and fs1 represents a focal length of the positive lens closest to the image in the first lens group.

Inventors:
NASU, Sachiko (6-10-1 Nishi-Shinjuku Shinjuku-k, Tokyo 47, 〒1608347, JP)
Application Number:
JP2019/006027
Publication Date:
August 29, 2019
Filing Date:
February 19, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HOYA CORPORATION (6-10-1 Nishi-Shinjuku, Shinjuku-ku Tokyo, 47, 〒1608347, JP)
International Classes:
G02B13/04; A61B1/00; G02B15/16; G02B15/163; G02B23/26
Domestic Patent References:
WO2017043352A12017-03-16
Foreign References:
JP2016161628A2016-09-05
JP2015215406A2015-12-03
JPS6287926A1987-04-22
JPH0519169A1993-01-29
JPH09152552A1997-06-10
JP2011247922A2011-12-08
JPH103038A1998-01-06
Attorney, Agent or Firm:
GLOBAL IP TOKYO (CARMEL II, 8-3-30 Nishi-Shinjuku, Shinjuku-k, Tokyo 23, 〒1600023, JP)
Download PDF: