Patent ID: 11953756
Assignee: JIANGXI OFILM OPTICAL CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. An optical system, successively in order from an object side to an image side, comprising:
a first lens having a positive refractive power, an object side surface of the first lens being convex at a circumference thereof;
a second lens having a refractive power;
a third lens having a refractive power;
a fourth lens having a refractive power;
a fifth lens having a refractive power;
a sixth lens having a positive refractive power;
a seventh lens having a negative refractive power, an image side surface of the seventh lens being concave at an optical axis; and
an eighth lens having a negative refractive power,
wherein the optical system satisfies the following conditions:

1<TTL/L<2.5;

wherein TTL is a distance from the object side surface of the first lens to an imaging surface of the optical system on the optical axis, and the optical system further comprises a stop, L is an effective aperture diameter of the stop;

TTL/Imgh<1.5;

wherein TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and Imgh is half of a length of a diagonal of an effective pixel area on the imaging surface;

1.0<TTL/|f|<1.5;

wherein TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and f is an effective focal length of the optical system;

f/f1≤1.2;

wherein f is an effective focal length of the optical system, and f1 is an effective focal length of the first lens; and

−0.6<f1/f2<0.1;

wherein f1 is an effective focal length of the first lens, and f2 is an effective focal length of the second lens.