US 12,228,702 B2
Imaging lens
Masaya Hashimoto, Tokyo (JP)
Assigned to TOKYO VISIONARY OPTICS Co., Ltd., Tokyo (JP)
Filed by TOKYO VISIONARY OPTICS CO., LTD., Tokyo (JP)
Filed on Aug. 2, 2021, as Appl. No. 17/391,930.
Application 17/391,930 is a continuation of application No. 17/220,610, filed on Apr. 1, 2021.
Claims priority of application No. 2020-067228 (JP), filed on Apr. 3, 2020.
Prior Publication US 2022/0163775 A1, May 26, 2022
Int. Cl. G02B 13/00 (2006.01); G02B 9/64 (2006.01); G02B 27/00 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 9/64 (2013.01); G02B 27/0025 (2013.01)] 7 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,
a second lens with positive refractive power,
a third lens with negative refractive power,
a fourth lens,
a fifth lens with positive refractive power,
a sixth lens with positive or negative refractive power, and
a seventh lens with negative refractive power,
wherein said imaging lens is configured with only seven lenses, said first lens is formed in a meniscus shape having an object-side surface being convex in a paraxial region, said second lens has an image-side surface being concave in a paraxial region, said sixth lens has an image-side surface being concave in a paraxial region, and said seventh lens has an image-side surface being concave in a paraxial region, and the following conditional expressions (1) and (9) are satisfied:
3.85<|r13/r14|  (1)
0.60<f1/f<2.30   (9)
where
r13: a paraxial curvature radius of an object-side surface of the seventh lens,
r14: a paraxial curvature radius of the image-side surface of the seventh lens,
f1: a focal length of the first lens, and
f: a focal length of the overall optical system of the imaging lens.