CPC G02B 9/62 (2013.01) [G02B 13/04 (2013.01); G02B 5/005 (2013.01); G02B 5/208 (2013.01)] | 19 Claims |
1. An optical imaging system comprising:
a first lens having a negative refractive power;
a second lens having a negative refractive power and a convex object-side surface in a paraxial region thereof;
a third lens having a positive refractive power;
a fourth lens having a positive refractive power and an object-side surface that is concave in a paraxial region thereof;
a fifth lens having a positive refractive power;
a sixth lens having a negative refractive power and an image-side surface that is concave in a paraxial region thereof, and a refractive index that is larger than the refractive indices of each of the first through fifth lenses,
wherein the first to sixth lenses are sequentially disposed in ascending numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system,
two lenses that are adjacent to each other among the first to sixth lenses are cemented to each other to form a cemented lens, and
TTL is in a range of 13.0 to 17.5, where TTL is a distance along an optical axis from an object-side surface of the first lens to the imaging plane.
|