US 12,072,476 B2
Optical system, optical apparatus, and method of manufacturing optical system
Masashi Yamashita, Tokyo (JP); Tomoki Ito, Kawasaki (JP); Hiroshi Yabumoto, Yokohama (JP); Hiroshi Yamamoto, Kawasaki (JP); Satoshi Miwa, Yokohama (JP); Keisuke Tsubonoya, Yokohama (JP); Ayumu Makida, Kawaguchi (JP); and Takeru Uehara, Ageo (JP)
Assigned to Nikon Corporation, Tokyo (JP)
Filed by Nikon Corporation, Tokyo (JP)
Filed on Apr. 10, 2023, as Appl. No. 18/132,463.
Application 18/132,463 is a division of application No. 16/771,668, granted, now 11,686,926, previously published as PCT/JP2017/045188, filed on Dec. 15, 2017.
Prior Publication US 2023/0244066 A1, Aug. 3, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 13/18 (2006.01); G02B 13/02 (2006.01); G02B 15/14 (2006.01); G02B 27/00 (2006.01)
CPC G02B 13/18 (2013.01) [G02B 13/02 (2013.01); G02B 15/144113 (2019.08); G02B 15/144511 (2019.08); G02B 15/1461 (2019.08); G02B 27/0062 (2013.01); G02B 15/1425 (2019.08); G02B 15/143105 (2019.08)] 22 Claims
OG exemplary drawing
 
1. An optical system comprising a lens satisfying following conditional expressions:
20.00<νdLZ<35.0
0.702<θgFLZ+(0.00316×νdLZ),
where
νdLZ: Abbe number of the specified lens with reference to d-line, and
θgFLZ: a partial dispersion ratio of the lens,
wherein θgFLZ is defined by the following expression,
θgFLZ=(ngLZ−nFLZ)/(nFLZ−nCLZ)
wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.