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Title:
OPTICAL SYSTEM, OPTICAL EQUIPMENT, AND OPTICAL-SYSTEM MANUFACTURING METHOD
Document Type and Number:
WIPO Patent Application WO/2019/116565
Kind Code:
A1
Abstract:
An optical system (LS) includes an aperture stop (S), and a positive lens (L22) that is disposed farther on the image side than the aperture stop (S) is and that satisfies the following conditional expressions: ndP2+(0.01425×νdP2) < 2.12; 18.0 <νdP2 < 35.0; and 0.702 <θgFP2+(0.00316×νdP2), where ndP2 is the refractive index of the positive lens with respect to the d-line, νdP2 is the Abbe number of the positive lens with reference to the d-line, and θgFP2 is the partial dispersion ratio of the positive lens. θgFP2 is defined by the following equation: θgFP2 = (ngP2-nFP2)/(nFP2-nCP2), assuming that the refractive index of the positive lens with respect to the g-line is ngP2, the refractive index of the positive lens with respect to the F-line is nFP2, and the refractive index of the positive lens with respect to the C-line is nCP2.

Inventors:
YAMASHITA, Masashi (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
ITO, Tomoki (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
YABUMOTO, Hiroshi (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
YAMAMOTO, Hiroshi (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
MIWA, Satoshi (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
TSUBONOYA, Keisuke (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
MAKIDA, Ayumu (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
UEHARA, Takeru (15-3 Konan 2-chome, Minato-k, Tokyo 90, 〒1086290, JP)
Application Number:
JP2017/045185
Publication Date:
June 20, 2019
Filing Date:
December 15, 2017
Export Citation:
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Assignee:
NIKON CORPORATION (15-3, Konan 2-chome Minato-k, Tokyo 90, 〒1086290, JP)
International Classes:
G02B13/00; G02B13/02; G02B13/04; G02B15/20
Foreign References:
JP2006301508A2006-11-02
JP2007025653A2007-02-01
JP2013218015A2013-10-24
JP2007322986A2007-12-13
JP2009280724A2009-12-03
JP2017190280A2017-10-19
Attorney, Agent or Firm:
OHNISHI, Shogo et al. (S.OHNISHI & ASSOCIATES, HIGASHI-IKEBUKURO SS BUILDING 1F 3-20-3, Higashi-Ikebukuro, Toshima-k, Tokyo 13, 〒1700013, JP)
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