Imaging lens system
An imaging lens system is provided. The imaging lens system includes a first lens having refractive power; a second lens having positive refractive power and having a concave image-side surface; a third lens having refractive power; a fourth lens having positive refractive power and having a concave image-side surface; a fifth lens having a concave object-side surface; a sixth lens having a concave image-side surface; a seventh lens having a convex object-side surface; and an eighth lens having refractive power, wherein the first to eighth lenses are sequentially arranged from an object-side to an imaging side, and the imaging lens system satisfies the following conditional expression: 0.15<BFL/TTL, where BFL is a distance from an image-side surface of the eighth lens to an imaging plane, and TTL is a distance from an object-side surface of the first lens to the imaging plane.
1 . An imaging lens system, comprising:
a first lens having a refractive power;
a second lens having positive refractive power, and having a concave image-side surface;
a third lens having a refractive power;
a fourth lens having positive refractive power, and having a concave image-side surface;
a fifth lens having a concave object-side surface;
a sixth lens having a concave image-side surface;
a seventh lens having a convex object-side surface; and
an eighth lens having a refractive power,
wherein the first to eighth lenses are sequentially arranged from an object-side to an imaging side, and
the imaging lens system satisfies the following conditional expression:
0.15< BFL/TTL,
where BFL is a distance from an image-side surface of the eighth lens to an imaging plane, and TTL is a distance from an object-side surface of the first lens to the imaging plane.
2 . The imaging lens system of claim 1 , wherein the first lens has a convex object-side surface.
3 . The imaging lens system of claim 1 , wherein the third lens has a convex object-side surface.
4 . The imaging lens system of claim 1 , wherein the eighth lens has a convex object-side surface.
5 . The imaging lens system of claim 1 , which satisfies the following conditional expression:
0< f 1/ f< 8.0,
where f is a focal length of the imaging lens system, and f 1 is a focal length of the first lens.
6 . The imaging lens system of claim 1 , which satisfies the following conditional expression:
0< f 2/ f< 3.0,
where f is a focal length of the imaging lens system, and f 2 is a focal length of the second lens.
7 . The imaging lens system of claim 1 , which satisfies the following conditional expression:
TTL/f< 1.5,
where f is a focal length of the imaging lens system.
8 . The imaging lens system of claim 1 , which satisfies the following conditional expression:
BFL/f< 0.4,
where f is a focal length of the imaging lens system.
9 . The imaging lens system of claim 1 , which satisfies the following conditional expression:
TTL/ 2ImgHT<0.8,
where 2ImgHT is a diagonal length of the imaging plane.
10 . An imaging lens system, comprising:
a first lens having positive refractive power;
a second lens having positive refractive power;
a third lens having a refractive power;
a fourth lens having a refractive power;
a fifth lens having a concave object-side surface;
a sixth lens having a refractive power;
a seventh lens having positive refractive power; and
an eighth lens having a refractive power, and a convex object-side surface in a paraxial region,
wherein the first to eighth lenses are sequentially arranged from an object-side to an imaging side, and
the imaging lens system satisfies the following conditional expression:
0.2< BFL/TTL< 0.35,
where BFL is a distance from an image-side surface of the eighth lens to an imaging plane, and TTL is a distance from an object-side surface of the first lens to the imaging plane.
11 . The imaging lens system of claim 10 , wherein the third lens has negative refractive power.
12 . The imaging lens system of claim 10 , wherein the eighth lens has negative refractive power.
13 . The imaging lens system of claim 10 , which satisfies the following conditional expression:
0.02< BFL/f 1<0.16,
where f1 is a focal length of the first lens.
14 . The imaging lens system of claim 10 , which satisfies the following conditional expression:
0.2< BFL/f 2<0.4,
where f2 is a focal length of the second lens.
15 . The imaging lens system of claim 10 , which satisfies the following conditional expression:
−0.3< BFL/f 3<−0.1,
where f3 is a focal length of the third lens.
16 . The imaging lens system of claim 10 , which satisfies the following conditional expression:
0.06< T 1/ImgHT<0.10,
Where T1 is a thickness of the first lens, and ImgHT is a height of the imaging plane.
17 . An electronic device, comprising the imaging lens system of claim 10 .