Patent ID: 11927827
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 having an object-side surface being convex in a paraxial region;
a third lens with negative refractive power having an object-side surface being concave in a paraxial region;
a fourth lens with negative refractive power in a paraxial region; and
a fifth lens with positive refractive power having an image-side surface being convex in a paraxial region,
wherein the imaging lens has a total of five single lenses, and
the following conditional expressions (1) and (2) are satisfied:

0.90<|r7|/f<4.00  (1)

0.15<r3/f<0.75  (2), where, r7: a paraxial curvature radius of an object-side surface of the fourth lens,, r3: a paraxial curvature radius of an object-side surface of the second lens, and, f: a focal length of the overall optical system of the imaging lens.