Patent ID: 8508649

Claim:
An optical imaging system for producing a real image of an object and having at least five lens elements arranged along an optical axis, comprising: a first lens group having a combined refractive power that is positive, comprising at least: a first lens element having positive refractive power and a meniscus shape; a second lens element having negative refractive power and a meniscus shape; a third lens element having a convex shape on an object side surface at least near the optical axis; a rear lens group having a combined refractive power that is negative, comprising one or two of the at least five lens elements; wherein: the optical imaging system satisfies at least one of the following two conditional expressions: ƒ 1 /ƒ<about 0.876 and ƒ 1 /ƒ G1 <about 1.238; or ƒ 1 /ƒ<about 1.27 and ƒ 1 /ƒ G1 <about 1.12, where ƒ 1 is a focal length of the first lens element, ƒ G1 is a combined focal length of the first lens group, and ƒ is a combined focal length of the optical imaging system.