Title:
OPTICAL SYSTEM, OPTICAL DEVICE, AND METHOD FOR MANUFACTURING OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2021/006002
Kind Code:
A1
Abstract:
An optical system (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. -020 <βF1/βF2 < 0.50 where βF1 is the lateral magnification of the first focusing lens group at the time of focusing on the infinite-distance object, and
βF2 is the lateral magnification of the second focusing lens group at the time of focusing on the infinite-distance object.
Inventors:
TSUBONOYA KEISUKE (JP)
Application Number:
PCT/JP2020/024055
Publication Date:
January 14, 2021
Filing Date:
June 19, 2020
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B13/00; G02B13/18
Domestic Patent References:
| WO2018135000A1 | 2018-07-26 |
Foreign References:
| JP2015034899A | 2015-02-19 | |||
| JP2017102354A | 2017-06-08 | |||
| JP2017223754A | 2017-12-21 | |||
| JPH11316341A | 1999-11-16 | |||
| JPS55140810A | 1980-11-04 | |||
| JP2019090949A | 2019-06-13 | |||
| JPS58219509A | 1983-12-21 | |||
| JP2019194630A | 2019-11-07 | |||
| JP2020064123A | 2020-04-23 |
Attorney, Agent or Firm:
OHNISHI, Shogo et al. (JP)
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