Two-piece type optical imaging lens

• Main Author: SHYU SAN-WOEI
• Format: Patent
• Language: English
• Published: 17.02.2009
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

A two-piece type optical imaging lens that includes a first lens element with positive refractive power, a second lens element with positive refractive power, an IR cut-off filter and an image sensor arranged along an optical axis in order from an object side. The first lens element and the second lens element are both meniscus aspherical molded glass lens while a convex surface of the first lens element is on the object side and a convex surface of the second lens is on the image side. The two-piece type optical imaging lens satisfies following conditions: 0.4f<=d<0.9f, 0.5f<=|R3|<=100f, 5<|f2|/|f1<15, and 20<=Vd<=60, wherein f is an effective focal length of the whole imaging lens, d is the distance between a convex surface on the object side of the first lens element and a convex surface on the image side of the second lens element, R3 is a radius of curvature of the object side of the second lens element, f1 is an effective focal length of the first lens element, f2 is an effective focal length of the second lens element and Vd is Abbe's number of the first lens element as well as the second lens element. Thus the lens has high resolution and minimized total length so that the lens volume is reduced and so does the cost. Therefore, the lens according to the present invention is more widely applicable.