Optical imaging system
An optical imaging system includes a first lens having refractive power, a second lens having refractive power and having a convex object-side surface, a third lens having refractive power and having a convex object-side surface, a fourth lens having refractive power, a fifth lens having refractive power, and a sixth lens having negative refractive power. The optical imaging system satisfies 100°≤FOV, and −2.0<{IMGHT/(f*tan(FOV/2))−1}*100<2.0, where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging plane, and f is a focal length of the optical imaging system.
1 . An optical imaging system comprising:
a first lens having positive refractive power and having a convex image-side surface in a paraxial region thereof;
a second lens having refractive power and having a convex object-side surface;
a third lens having refractive power and having a convex object-side surface;
a fourth lens having refractive power;
a fifth lens having refractive power and having a convex object-side surface in a paraxial region thereof; and
a sixth lens having negative refractive power,
wherein the first to sixth lenses are disposed in order from an object side,
wherein
100°≤FOV
−2.0<{IMGHT/( f *tan(FOV/2))−1}*100<2.0,
where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging plane, and f is a focal length of the optical imaging system,
wherein R8>R1, where R8 is a value of a radius of curvature of an image-side surface of the fourth lens and R1 is a value of a radius of curvature of an object-side surface of the first lens,
wherein R7>R6, where R7 is a value of a radius of curvature of an object-side surface of the fourth lens and R6 is a value of a radius of curvature of an image-side surface of the third lens,
wherein a thickness of the fourth lens is greater than a thickness of the first lens,
wherein a distance from an image-side surface of the fifth lens to an object-side surface of the sixth lens is greater than a distance from an image-side surface of the second lens to an object-side surface of the third lens, and
wherein the distance from the image-side surface of the fifth lens to the object-side surface of the sixth lens is greater than the thickness of the first lens.
2 . The optical imaging system of claim 1 , wherein the first lens has a concave object-side surface.
3 . The optical imaging system of claim 1 , wherein the fourth lens has a concave object-side surface.
4 . The optical imaging system of claim 1 , wherein the sixth lens has a convex object-side surface.
5 . The optical imaging system of claim 1 , wherein the sixth lens has a concave image-side surface.
6 . The optical imaging system of claim 1 , wherein
−1.5< f 3/ f 4<−0.7,
where f4 is a focal length of the fourth lens.
7 . The optical imaging system of claim 1 , wherein
0.6<| f 4/ f 6|<1.8,
where f4 is a focal length of the fourth lens, and f6 is a focal length of the sixth lens.
8 . The optical imaging system of claim 1 , wherein
1.3 <TTL /IMGHT<1.4,
where TTL is a distance from the object-side surface of the first lens to the imaging plane.
9 . The optical imaging system of claim 1 , wherein
1.8<f number<2.3, where f number is an f number of the optical imaging system.
10 . An optical imaging system comprising:
a first lens having positive refractive power and having a convex image-side surface in a paraxial region thereof;
a second lens having refractive power and having a convex object-side surface;
a third lens having refractive power and having a convex object-side surface;
a fourth lens having refractive power;
a fifth lens having refractive power and having a convex object-side surface in a paraxial region thereof; and
a sixth lens having refractive power,
wherein the first to sixth lenses are disposed in order from an object side,
wherein
100°≤FOV, and
−2.0<{IMGHT/( f *tan(FOV/2))−1}*100<2.0,
where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging plane, and f is a focal length of the optical imaging system,
wherein R8>R1, where R8 is a value of a radius of curvature of an image-side surface of the fourth lens and R1 is a value of a radius of curvature of an object-side surface of the first lens,
wherein R7>R6, where R7 is a value of a radius of curvature of an object-side surface of the fourth lens and R6 is a value of a radius of curvature of an image-side surface of the third lens,
wherein a thickness of the fourth lens is greater than a thickness of the first lens,
wherein a distance from an image-side surface of the fifth lens to an object-side surface of the sixth lens is greater than a distance from an image-side surface of the second lens to an object-side surface of the third lens, and
wherein the distance from an image-side surface of the fifth lens to an object-side surface of the sixth lens is greater than the thickness of the first lens.
11 . The optical imaging system of claim 10 , wherein the first lens has refractive power having a sign different from a sign of the refractive power of the second lens.
12 . The optical imaging system of claim 10 , wherein the fourth lens has refractive power having a sign different from a sign of the refractive power of the fifth lens.
13 . The optical imaging system of claim 10 , wherein the sixth lens has negative refractive power.
14 . The optical imaging system of claim 10 , wherein the sixth lens has a convex object-side surface.
15 . The optical imaging system of claim 10 , wherein
1.0 <f 1 /f 3<3.0,
where f1 is a focal length of the first lens.
16 . The optical imaging system of claim 10 , wherein TTL/IMGHT<1.4, where TTL is a distance from the object-side surface of the first lens to the imaging plane.