CPC G02B 13/0045 (2013.01) [G02B 9/64 (2013.01); G02B 13/18 (2013.01); G02B 27/0025 (2013.01)] | 6 Claims |
1. An imaging lens forming an image of an object on an image sensor and comprising, in order from an object side to an image side,
a first lens with positive refractive power,
a second lens with negative refractive power,
a third lens with positive refractive power,
a fourth lens with negative refractive power,
a fifth lens,
a sixth lens,
a seventh lens with positive refractive power, and
an eighth lens with negative refractive power,
wherein said fourth lens is formed in a shape that curvature radii of an object-side surface and an image-side surface are both negative,
said eighth lens has an aspheric image-side surface having at least one inflection point, and
the following conditional expressions are satisfied:
0.04<D34/f<0.15,
(9′) 1.00<R7r/R7f<=2.08 (9′)
where
f: a focal length of the overall optical system of the imaging lens,
D34: a distance along the optical axis between the third lens and the fourth lens,
R7f: a curvature radius of an object-side surface of the seventh lens, and
R7r: a curvature radius of an image-side surface of the seventh lens.
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