US 12,270,975 B2
Imaging optical system and imaging apparatus
Naomichi Kikuchi, Tokyo (JP); and Miki Nakayama, Tokyo (JP)
Assigned to SONY GROUP CORPORATION, Tokyo (JP)
Appl. No. 17/753,824
Filed by SONY GROUP CORPORATION, Tokyo (JP)
PCT Filed Aug. 5, 2020, PCT No. PCT/JP2020/030000
§ 371(c)(1), (2) Date Mar. 16, 2022,
PCT Pub. No. WO2021/059763, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 2019-174200 (JP), filed on Sep. 25, 2019.
Prior Publication US 2022/0346631 A1, Nov. 3, 2022
Int. Cl. G02B 13/02 (2006.01); G02B 5/30 (2006.01)
CPC G02B 13/02 (2013.01) [G02B 5/3083 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An imaging optical system comprising:
an aperture stop;
an image-forming optical system that causes an image to be formed toward an imaging plane of an image sensor; and
an optical phase modulator that includes a substance having a birefringence index, and gives two pupil functions to the image-forming optical system, wherein
the following conditional expressions are satisfied:
1≤(2×L×tan(w)+D)/D<1.4  (1)
λ/4*0.75<Re<λ/4*1.1  (2), where
L: a distance between the aperture stop and the optical phase modulator;
D: an aperture diameter (diameter) of the aperture stop;
w: a maximum angle of incidence of a principal light ray that enters the aperture stop;
λ: a wavelength of light; and
Re: phase retardation caused by birefringence of the optical phase modulator.