Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
ENDOSCOPIC OBJECTIVE OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2019/180984
Kind Code:
A1
Abstract:
The present invention provides an endoscopic objective optical system which has a long back focus, allows focusing, and suitably corrects aberrations. The endoscopic objective optical system includes in order from an object: a first lens group G1 having a negative refractive power; a second lens group G2 having a positive refractive power; and a third lens group G3 having a positive refractive power. The second lens group G2 has a brightness stop S, and moves when magnification is changed The endoscopic objective optical system satisfies the following conditional expression (1): 1 < (Lb × f3) / (Lf × f12) < 9 (1) Where Lb represents the length from the surface closest to an object in the third lens group to an image surface, f3 represents the focal length of the third lens group, Lf represents a length from the surface closest to the object in the first lens group to the surface closest to the object in the third lens group, and f12 represents the composite focal length of the first lens group and the second lens group at a wide angle end.

More Like This:
Inventors:
SONE Nobuhiko (2951 Ishikawa-machi, Hachioji-sh, Tokyo 07, 〒1928507, JP)
Application Number:
JP2018/030467
Publication Date:
September 26, 2019
Filing Date:
August 17, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
OLYMPUS CORPORATION (2951, Ishikawa-machi Hachioji-sh, Tokyo 07, 〒1928507, JP)
International Classes:
G02B15/14; G02B13/04
Domestic Patent References:
WO2017043352A12017-03-16
WO2017145264A12017-08-31
Foreign References:
JP2007093961A2007-04-12
JP2012037768A2012-02-23
Attorney, Agent or Firm:
SAITO Keisuke (Surugadai-shita MK Bldg. 6F, 41-3 Kanda-jimbocho 1-chome, Chiyoda-k, Tokyo 51, 〒1010051, JP)
Download PDF: