CPC G02B 9/60 (2013.01) [G02B 13/0045 (2013.01); G02B 27/0025 (2013.01)] | 6 Claims |
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 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, and
a fifth lens with negative refractive power having a convex image-side surface in a paraxial region, wherein the following conditional expressions (1), (2), (3) and (8) are satisfied:
48.00<νd3<70.00 (1)
0.20<|r2|/f<8.00 (2)
−2.30<|r2|/r3/r10<−0.45 (3)
0.05<D3/T3<0.25 (8)
where
νd3: an abbe number at d-ray of the third lens,
f: a focal length of an overall optical system of the imaging lens,
r2: a paraxial curvature radius of an image-side surface of the first lens,
r3: a paraxial curvature radius of an object-side surface of the second lens,
r10: a paraxial curvature radius of an image-side surface of the fifth lens,
D3: a thickness along the optical axis of the third lens, and
T3: a distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens.
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