Patent ID: 11867880
Assignee: ZHEJIANG SUNNY OPTICAL CO., LTD
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 13:
14. An optical imaging system, sequentially from an object side to an image side of the optical imaging system along an optical axis, comprising:
a first lens having refractive power;
a second lens having negative refractive power;
a third lens having refractive power;
a fourth lens having positive refractive power;
a fifth lens having refractive power;
a sixth lens having refractive power; and
a seventh lens having refractive power, an object-side surface of the seventh lens is a concave surface, and an image-side surface of the seventh lens is a concave surface,
wherein 1.15<f6/f<1.65, and

−4<SAG61/(SAG62−SAG71)<−1,

where f6 is an effective focal length of the sixth lens,
f is a total effective focal length of the optical imaging system,
SAG61 is a distance along the optical axis from an intersection of an object-side surface of the sixth lens and the optical axis to a vertex of an effective radius of the object-side surface of the sixth lens,
SAG62 is a distance along the optical axis from an intersection of an image-side surface of the sixth lens and the optical axis to a vertex of an effective radius of the image-side surface of the sixth lens, and
SAG71 is a distance along the optical axis from an intersection of the object-side surface of the seventh lens and the optical axis to a vertex of an effective radius of the object-side surface of the seventh lens.