US 11,988,813 B2
Imaging lens
Huang Zhiyu, Tokyo (JP)
Assigned to TOKYO VISIONARY OPTICS Co., Ltd., Tokyo (JP)
Filed by TOKYO VISIONARY OPTICS CO., LTD., Tokyo (JP)
Filed on Dec. 3, 2020, as Appl. No. 17/111,062.
Claims priority of application No. 2019-219061 (JP), filed on Dec. 3, 2019.
Prior Publication US 2022/0011544 A1, Jan. 13, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 13/00 (2006.01); G02B 9/62 (2006.01); G02B 27/00 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 9/62 (2013.01); G02B 27/0025 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An imaging lens comprising in order from an object side to an image side,
a first lens with positive refractive power being formed in a meniscus shape having an object-side surface being convex in a paraxial region,
a second lens with positive refractive power in a paraxial region,
a third lens with negative refractive power in a paraxial region,
a fourth lens with positive refractive power in a paraxial region,
a fifth lens having aspheric surfaces on both sides, and
a sixth lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the following conditional expressions (1), (2) and (3) are satisfied:
0.30<f1/f4<1.85  (1)
−3.30<r6/f<−0.70  (2)
15.00<vd6<36.00  (3)
where
f1: a focal length of the first lens,
f4: a focal length of the fourth lens,
r6: a paraxial curvature radius of an image-side surface of the third lens,
f: a focal length of the overall optical system of the imaging lens, and
vd6: an abbe number at d-ray of the sixth lens.