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Patent Searching and Data


Title:
VARIABLE POWER OPTICAL SYSTEM FOR STEREO MICROSCOPE
Document Type and Number:
WIPO Patent Application WO/2010/073565
Kind Code:
A1
Abstract:
Disclosed is a variable power optical system for a stereo microscope comprising a first lens group (G1) having a positive refracting power, a second lens group (G2) having a negative refracting power, an aperture stop (S), a third lens group (G3) having a positive refracting force, and a fourth lens group (G4) having a negative refracting force. These components are arranged in this order from the object side. The second lens group (G2) consists of a front lens group (G2F) having a negative refracting power, and a rear lens group (G2R) having an achromatic cemented lens including a positive lens and a negative lens. The second lens group (G2) and the third lens group (G3) are moved along an optical axis in opposite directions at least in a part of a variable power section. When it is assumed that the focal length of the second lens group (G2) is f2, the focal length of the front lens group (G2F) of the second lens group is f2F, and the shape factor of the negative lens of the front lens group (G2F) of the second lens group that is located on the side closest to an object to be taken is q2, the following formulae are satisfied; 0.4 < f2F/f2 < 1.6 and -3.0 < q2 < -0.3.

Inventors:
MIZUTA, Masahiro (C/O NIKON CORPORATION, 2-3 Marunouchi 3-chome, Chiyoda-k, Tokyo 31, 〒1008331, JP)
水田正宏 (〒31 東京都千代田区丸の内三丁目2番3号 株式会社ニコン内 Tokyo, 〒1008331, JP)
Application Number:
JP2009/007001
Publication Date:
July 01, 2010
Filing Date:
December 18, 2009
Export Citation:
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Assignee:
NIKON CORPORATION (12-1, Yurakucho 1-Chome Chiyoda-k, Tokyo 31, 〒1008331, JP)
株式会社ニコン (〒31 東京都千代田区有楽町一丁目12番1号 Tokyo, 〒1008331, JP)
MIZUTA, Masahiro (C/O NIKON CORPORATION, 2-3 Marunouchi 3-chome, Chiyoda-k, Tokyo 31, 〒1008331, JP)
International Classes:
G02B15/167; G02B21/22
Attorney, Agent or Firm:
OHNISHI, Shogo (S.OHNISHI & ASSOCIATES, HIGASHI-IKEBUKURO SS BUILDING 1F 3-20-3, Higashi-Ikebukuro, Toshima-k, Tokyo 13, 〒1700013, JP)
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