Patent ID: 11899180
Assignee: TOKYO VISIONARY OPTICS CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An imaging lens comprising, in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region, a second lens with negative refractive power in a paraxial region, a third lens with negative refractive power having an object-side surface being convex in a paraxial region, a fourth lens having an object-side surface being convex in a paraxial region, a fifth lens with negative refractive power in a paraxial region, and a sixth lens with positive refractive power having an image-side surface being convex in a paraxial region, wherein the following conditional expressions (1), (2) and (3) are satisfied:

11.00<vd2<27.00  (1)

−1.55<f3/f<−0.20  (2)

0.25<r3/f<5.00  (3)

where
vd2: an abbe number at d-ray of the second lens,
f3: a focal length of the third lens,
f: a focal length of the overall optical system of the imaging lens, and
r3: a paraxial curvature radius of an object-side surface of the second lens, and
wherein an image-side surface of said first lens is convex in a paraxial region.