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Title:
OPTICAL SYSTEM, OPTICAL EQUIPMENT, AND OPTICAL SYSTEM MANUFACTURING METHOD
Document Type and Number:
WIPO Patent Application WO/2019/116564
Kind Code:
A1
Abstract:
An optical system (LS) includes an aperture stop (S), and a negative lens (L15) that is disposed farther on the object side than the aperture stop (S) is and satisfies the following conditional expressions: ndN1+(0.01425×νdN1) < 2.12; 18.0 <νdN1 < 35.0; and 0.702 <θgFN1+(0.00316×νdN1), where ndN1 is the refractive index of the negative lens with respect to the d-line, νdN1 is the Abbe number of the negative lens using the d-line as a reference, and θgFN1 is the partial dispersion ratio of the negative lens. θgFN1 is defined as θgFN1 = (ngN1-nFN1)/(nFN1-nCN1), assuming that the refractive index of the negative lens with respect to the g-line is ngN1, the refractive index of the negative lens with respect to the F-line is nFN1, and the refractive index of the negative lens with respect to the C-line is nCN1.

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Inventors:
YAMASHITA MASASHI (JP)
ITO TOMOKI (JP)
YABUMOTO HIROSHI (JP)
YAMAMOTO HIROSHI (JP)
MIWA SATOSHI (JP)
TSUBONOYA KEISUKE (JP)
MAKIDA AYUMU (JP)
UEHARA TAKERU (JP)
Application Number:
PCT/JP2017/045184
Publication Date:
June 20, 2019
Filing Date:
December 15, 2017
Export Citation:
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Assignee:
NIKON CORP (JP)
International Classes:
G02B13/00; G02B13/02; G02B13/04; G02B15/20
Foreign References:
JP2010060612A2010-03-18
JP2010139766A2010-06-24
JPS60198512A1985-10-08
JP2009280724A2009-12-03
JP2017190280A2017-10-19
Attorney, Agent or Firm:
OHNISHI, Shogo et al. (JP)
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