Optical imaging system
An optical imaging system includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens, a fifth lens, and a sixth lens having a positive refractive power and having a convex image-side shape, sequentially arranged in a direction from an object side of the optical imaging system to an imaging plane of the optical imaging system.
1. An optical imaging system, comprising:
a first lens comprising a convex image-side surface;
a second lens comprising a refractive power;
a third lens comprising a refractive power;
a fourth lens comprising positive refractive power and a convex object-side surface;
a fifth lens comprising a refractive power; and
a sixth lens comprising positive refractive power and a convex image-side surface,
wherein the first to sixth lenses are sequentially disposed from an object side toward an imaging plane,
wherein the optical imaging system comprises a total number of six lenses comprising refractive power, and
wherein an absolute value of a radius of curvature of an object-side surface of the fourth lens is greater than an absolute value of a radius of curvature of an object-side surface of the third lens.
2. The optical imaging system of claim 1 , wherein the second lens has a concave image-side surface.
3. The optical imaging system of claim 1 , wherein the third lens has a concave object-side surface.
4. The optical imaging system of claim 1 , wherein the third lens has a concave image-side surface.
5. The optical imaging system of claim 1 , wherein the fifth lens has a concave image-side surface.
6. The optical imaging system of claim 1 , wherein:
0.7< TL/f< 1.0,
where TL is a distance from an object-side surface of the first lens to the imaging plane and f is a total focal length of the optical imaging system.
7. The optical imaging system of claim 1 , wherein:
0.15< R 1/ f< 0.32,
where f is a total focal length of the optical imaging system and R1 is a radius of curvature of an object-side surface of the first lens.
8. The optical imaging system of claim 1 , wherein:
−3.5< f/f 2<−0.5,
where f is a total focal length of the optical imaging system and f2 is a focal length of the second lens.
9. An optical imaging system, comprising:
a first lens comprising a convex image-side surface;
a second lens comprising a refractive power;
a third lens comprising a refractive power;
a fourth lens comprising positive refractive power and a convex object-side surface;
a fifth lens comprising a refractive power; and
a sixth lens comprising positive refractive power and a convex image-side surface,
wherein the first to sixth lenses are sequentially disposed from an object side toward an imaging plane,
wherein a radius of curvature of an object-side surface of the fifth lens is greater than a radius of curvature of an object-side surface of the third lens, and
wherein:
0.15< R 1/ f< 0.32,
where f is a total focal length of the optical imaging system and R1 is a radius of curvature of an object-side surface of the first lens.