US 12,072,478 B2
Optical system and imaging apparatus including the same
Takumi Suzuki, Utsunomiya (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Aug. 18, 2022, as Appl. No. 17/820,846.
Application 17/820,846 is a continuation of application No. 16/592,391, filed on Oct. 3, 2019, granted, now 11,467,385.
Claims priority of application No. 2018-194671 (JP), filed on Oct. 15, 2018.
Prior Publication US 2022/0404596 A1, Dec. 22, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 15/14 (2006.01); G02B 15/22 (2006.01)
CPC G02B 15/145105 (2019.08) [G02B 15/145103 (2019.08); G02B 15/145113 (2019.08); G02B 15/145121 (2019.08); G02B 15/145511 (2019.08); G02B 15/1461 (2019.08); G02B 15/22 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An optical system in which an interval between adjacent lens units is configured to change during focusing from an infinite-distance object to a close-distance object, and in which in a first in-focus state β=−1.2 is satisfied, where β is a lateral magnification of the optical system, the optical system comprising:
two focus lens units configured to move during focusing from an infinite-distance object to a close-distance object; and
an aperture stop,
wherein the two focus lens units include a first focus lens unit (LA) disposed on an object side and a second focus lens unit (LB) disposed on an image side,
wherein the second focus lens unit (LB) has negative refractive power as a whole, and includes a biconcave lens and a positive lens with a convex surface on an image side, the positive lens being disposed on an image side of the biconcave lens, and
wherein the following inequality is satisfied:
0.50<Di/f<1.50,
where Di is a distance from the aperture stop to an image plane in an in-focus state on an infinite-distance object and f is a focal length of the optical system in an in-focus state on an infinite-distance object.