Imaging lens system
An imaging lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens disposed in order from an object side. In the imaging lens system, the first lens has positive refractive power and an object-side surface of the first lens is concave. A field of view of the imaging lens system is 100 degrees or more. In the imaging lens system, a distance TTL from the object-side surface of the first lens to an imaging plane and a height ImgH of the imaging plane satisfy TTL/ImgH<1.5.
1. An imaging lens system comprising:
a first lens having positive refractive power and comprising a concave object-side surface, a second lens having negative refractive power, a third lens, a fourth lens, a fifth lens having negative refractive power, a sixth lens comprising a concave image-side surface in a paraxial region, and a seventh lens disposed in order from an object side,
wherein a field of view of the imaging lens system is 100 degrees or more, and
wherein TTL/ImgH<1.5, where TTL is a distance from the object-side surface of the first lens to an imaging plane and ImgH is a height of the imaging plane.
2. The imaging lens system of claim 1 , wherein the third lens has positive refractive power.
3. The imaging lens system of claim 1 , wherein an object-side surface of the fourth lens is convex.
4. The imaging lens system of claim 1 , wherein an object-side surface of the fifth lens is concave.
5. The imaging lens system of claim 1 , wherein the sixth lens has positive refractive power.
6. The imaging lens system of claim 5 , wherein the seventh lens has negative refractive power.
7. The imaging lens system of claim 1 , wherein
−2.0<(Img H /( f *tan(FOV/2))−1)*100<2.0,
where f is a focal length of the imaging lens system and FOV is a field of view of the imaging lens system.
8. The imaging lens system of claim 1 , wherein
D 12/ D 23<0.14,
where D12 is a distance from an image-side surface of the first lens to an object-side surface of the second lens and D23 is a distance from an image-side surface of the second lens to an object-side surface of the third lens.
9. The imaging lens system of claim 1 , wherein
1.2< D 23/ D 34,
where D23 is a distance from an image-side surface of the second lens to an object-side surface of the third lens and D34 is a distance from an image-side surface of the third lens to an object-side surface of the fourth lens.
10. The imaging lens system of claim 1 , wherein
−0.2< f 3/ f 2<−0.04,
where f2 is a focal length of the second lens and f3 is a focal length of the third lens.
11. An imaging lens system comprising:
a plurality of lenses disposed on an object-side of an imaging plane, the plurality of lenses including a first lens, a second lens having negative refractive power, a third lens, a fourth lens, a fifth lens, a sixth lens comprising a concave image-side surface in a paraxial region, and a seventh lens disposed in order from an object side,
wherein
−2.0<(Img H /( f *tan(FOV/2))−1)*100<2.0, and
TTL/Img H <1.5,
where ImgH is a height of the imaging plane, f is a focal length of the imaging lens system, FOV is a field of view of the imaging lens system, and TTL is a distance from an object-side surface of a lens, from among the plurality of lenses, disposed closest to the object side, to the imaging plane, and
wherein a radius of curvature of an object-side surface of the second lens is greater than a radius of curvature of an object-side surface of the seventh lens.
12. The imaging lens system of claim 11 , wherein the field of view of the imaging lens system is 100 degree or more.
13. The imaging lens system of claim 11 , wherein the first lens has positive refractive power and an object-side surface that is concave.
14. The imaging lens system of claim 11 , wherein
1.6<TTL/ f <1.8.
15. The imaging lens system of claim 11 , wherein
0.2 <T max/Img H <0.3,
where Tmax is a thickness of a center of a lens having the highest thickness in a center of an optical axis, among the plurality of lenses.