US 12,306,466 B2
Optical imaging system
Jae Hyuk Huh, Suwon-si (KR); Byung Hyun Kim, Suwon-si (KR); So Mi Yang, Suwon-si (KR); and Yong Joo Jo, Suwon-si (KR)
Assigned to Samsung Electro-Mechanics Co., Ltd., Suwon-si (KR)
Filed by Samsung Electro-Mechanics Co., Ltd., Suwon-si (KR)
Filed on Jul. 11, 2023, as Appl. No. 18/350,201.
Application 18/350,201 is a continuation of application No. 16/997,045, filed on Aug. 19, 2020, granted, now 11,796,760.
Claims priority of application No. 10-2020-0053742 (KR), filed on May 6, 2020.
Prior Publication US 2023/0350161 A1, Nov. 2, 2023
Int. Cl. G02B 9/60 (2006.01); G02B 13/00 (2006.01)
CPC G02B 9/60 (2013.01) [G02B 13/0045 (2013.01); G02B 13/0065 (2013.01)] 9 Claims
OG exemplary drawing
 
1. An optical imaging system comprising:
a first lens having a refractive power;
a second lens having a refractive power and a concave image-side surface in an optical axis region thereof;
a third lens having a refractive power;
a fourth lens having a concave object-side surface in an optical axis region thereof; and
a fifth lens having a concave object-side surface in an optical axis region thereof,
wherein the first to fifth lenses are sequentially disposed in ascending numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system,
a thickness of the fourth lens along the optical axis is greater than a thickness of the fifth lens along the optical axis,
a radius of curvature of an object-side surface of the third lens is greater than a radius of curvature of an image-side surface of the first lens, and
the following conditional expressions are satisfied:
|f/f1+f/f2|<1.2
R1/f≤0.265
0.2<(D23+D34+D45)/BFL<0.5
where f is a focal length of the optical imaging system, f1 is a focal length of the first lens, f2 is a focal length of the second lens, R1 is a radius of curvature of an object-side surface of the first lens, D23 is a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens, D34 is a distance along the optical axis from an image-side surface of the third lens to the object-side surface of the fourth lens, D45 is a distance along the optical axis from an image-side surface of the fourth lens to the object-side surface of the fifth lens, and BFL is a distance along the optical axis from an image-side surface of the fifth lens to the imaging plane.