US 12,339,423 B2
Small lens system for developing close tolerance
Soon Cheol Choi, Gyeonggi-do (KR); Ki Youn Noh, Gyeonggi-do (KR); and Seong Jun Bae, Gyeonggi-do (KR)
Assigned to SEKONIX CO., LTD., Gyeonggi-do (KR)
Filed by SEKONIX CO., LTD., Gyeonggi-do (KR)
Filed on Mar. 25, 2022, as Appl. No. 17/704,534.
Claims priority of application No. 10-2021-0040852 (KR), filed on Mar. 30, 2021.
Prior Publication US 2022/0326489 A1, Oct. 13, 2022
Int. Cl. G02B 13/18 (2006.01); G02B 3/00 (2006.01); G02B 9/62 (2006.01); G02B 13/00 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 3/0043 (2013.01); G02B 9/62 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A small lens system for developing a close tolerance, the small lens system comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens that are arranged in order along an optical axis from an object,
wherein refractive power P1 of the first lens satisfies −0.01 mm−1<P1<0.01 mm−1,
the second lens is shaped with opposite convex surfaces, and refractive power P2 of the second lens satisfies P2>0.4 mm−1,
the third lens has negative refractive power, and a rear surface curvature C6 of the third lens satisfies −0.01 mm−1<C6<0.01 mm−1,
refractive power P4 of the fourth lens satisfies −0.1 mm−1<P4<0.1 mm−1,
refractive power P5 of the fifth lens satisfies P5>0.7 mm−1, and
refractive power P6 of the sixth lens satisfies P6<−0.7 mm−1, an object-side surface of the sixth lens has at least one inflection point and amount of sagittal (sag) is increased and reduced in response to height of the sixth lens, and an image-side surface of the sixth lens has at least one inflection point and amount of sag is increased and reduced in response to the height thereof.