US 11,835,687 B2
Imaging lens
Kenichi Kamada, Sukagawa (JP); and Masaya Hashimoto, Sakagawa (JP)
Assigned to TOKYO VISIONARY OPTICS CO., LTD., Tokyo (JP)
Filed by TOKYO VISIONARY OPTICS CO., LTD., Tokyo (JP)
Filed on Nov. 3, 2020, as Appl. No. 17/088,077.
Application 17/088,077 is a continuation of application No. 16/744,798, filed on Jan. 16, 2020, abandoned.
Claims priority of application No. 2019-006312 (JP), filed on Jan. 17, 2019.
Prior Publication US 2021/0382275 A1, Dec. 9, 2021
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)] 8 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 having a convex object-side surface in a paraxial region, a second lens with negative refractive power having a concave image-side surface in a paraxial region,
a third lens having a convex object-side surface in a paraxial region,
a fourth lens having a convex image-side surface in a paraxial region,
a fifth lens with positive refractive power having a convex object-side surface in a paraxial region, and
a sixth lens having a concave image-side surface in a paraxial region,
wherein three out of four lenses from the third lens to the sixth lens have positive refractive power or negative refractive power in the paraxial region, and
one out of the four lenses is formed in a meniscus shape in the paraxial region, substantially has no refractive power in the paraxial region, and has aspheric surfaces on both sides, and the following conditional expressions (1) and (5) are satisfied:
1E6 mm<|fCNE|mm  (1)
8.30<(D1/f1)×100<13.00  (5)
where
fCNE: a focal length of a lens substantially having no refractive power,
D1: a thickness of the first lens along the optical axis, and
F1: a focal length of the first lens.