Title:
WIDE-ANGLE OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2016/204091
Kind Code:
A1
Abstract:
Provided is a wide-angle optical system wherein color aberration for magnification is excellently corrected.
The wide-angle optical system is provided with, in order from the forward object side, a first lens group G1 having negative refractive power, a second lens group G2 having a catadioptric optical element L3, an aperture stop S, and a third lens group G3 having positive refractive power. The first lens group G1 includes a positive lens L1 and a negative lens L2. The catadioptric optical element L3 has a first surface R1, a second surface R2, and a third surface R3 formed between the first surface R1 and the second surface R2. The first surface R1 has a first transmitting surface R1T and a first reflective surface R1R, the second surface R2 has a second transmitting surface R2T and a second reflective surface R2R, and the third surface R3 has a third transmitting surface R3T. The third transmitting surface R3T is a side surface of a circular truncated cone, and the vertex of the circular truncated cone is positioned more to the forward object side than the first lens group G1. The wide-angle optical system satisfies the following conditions (1), (2) and (3).
νp <νn (1)
|φp| < |φn| (2)
90 − θk <α/2 (3)
Inventors:
MIZUSAWA MASAYUKI (JP)
Application Number:
PCT/JP2016/067388
Publication Date:
December 22, 2016
Filing Date:
June 10, 2016
Export Citation:
Assignee:
OLYMPUS CORP (JP)
International Classes:
G02B13/04; G02B17/08; G02B13/06; G02B13/18; G02B15/15
Foreign References:
| JP2008309861A | 2008-12-25 | |||
| JP2011075915A | 2011-04-14 |
Other References:
See also references of EP 3312655A4
Attorney, Agent or Firm:
SAITO Keisuke et al. (JP)
Keisuke Saito (JP)
Keisuke Saito (JP)
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