| CPC G02B 9/64 (2013.01) [G02B 1/041 (2013.01); G02B 7/021 (2013.01); G02B 13/0045 (2013.01); G02B 27/0025 (2013.01); G02B 7/028 (2013.01)] | 14 Claims |

|
1. An optical imaging system comprising:
a first lens having a refractive power and a convex object-side surface in an optical axis region thereof;
a second lens having a negative refractive power;
a third lens having a refractive power and a convex object-side surface in an optical axis region thereof;
a fourth lens having a refractive power;
a fifth lens having a refractive power and a convex object-side surface in an optical axis region thereof;
a sixth lens having a positive refractive power; and
a seventh lens having a negative refractive power,
wherein the first to seventh lenses are sequentially disposed in ascending numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system,
the optical imaging system has a total of seven lenses having a refractive power,
0.25< (D12+D23+D34+D45+D56+D67)/6<0.7, where D12 is a distance along the optical axis from an image-side surface of the first lens to an object-side surface of the second lens, D23 is a distance along the optical axis from an image-side surface of the second lens to the object-side surface of the third lens, D34 is a distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens, D45 is a distance along the optical axis from an image-side surface of the fourth lens to the object-side surface of the fifth lens, D56 is a distance along the optical axis from an image-side surface of the fifth lens to an object-side surface of the sixth lens, and D67 is a distance along the optical axis from an image-side surface of the sixth lens to an object-side surface of the seventh lens,
a radius of curvature of the object-side surface of the third lens on the optical axis is greater than a radius of curvature of the object-side surface of the fifth lens on the optical axis,
a radius of curvature of the image-side surface of the third lens on the optical axis is greater than a radius of curvature of an image-side surface of the seventh lens on the optical axis,
a radius of curvature of the object-side surface of the fourth lens on the optical axis is greater than a radius of curvature of the image-side surface of the seventh lens on the optical axis, and
D23 is greater than a thickness of the second lens along the optical axis.
|