US 12,455,436 B2
Optical system and image pickup apparatus
Yuma Kobayashi, Tochigi (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Jan. 18, 2023, as Appl. No. 18/155,805.
Claims priority of application No. 2022-013869 (JP), filed on Feb. 1, 2022.
Prior Publication US 2023/0244065 A1, Aug. 3, 2023
Int. Cl. G02B 13/00 (2006.01); G02B 9/12 (2006.01); G02B 23/24 (2006.01)
CPC G02B 13/006 (2013.01) [G02B 9/12 (2013.01); G02B 23/243 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An optical system consisting of, in order from an object side to an image side, a first unit, a second unit, and a third unit,
wherein the first unit includes a first substrate, a first lens disposed on the object side of the first substrate, and a second lens having negative power and disposed on the image side of the first substrate,
wherein the second unit includes a second substrate and a third lens having positive power and disposed on the object side of the second substrate, and an aperture stop disposed on the second substrate and closer to the image side than the third lens,
wherein the third unit includes a third substrate and a fourth lens having positive power and disposed on the object side or the image side of the third substrate, and
wherein at least one of the following inequalities are satisfied:
−1.000≤f×(1/r9−1/r0)≤0.700
−1.000≤f×(1/r7−1/r0)≤0.600
where r0, r7, and r9 are radii of curvature at positions on an optical axis of the first lens, 70% of an effective radius of the first lens, and 90% of the effective radius of the first lens, respectively, and f is a focal length of the optical system.