| US 7,570,436 B2 | ||
| Two piece type optical lens | ||
| San-Woei Shyu, Taipei (Taiwan); and Chi-Hsiung Wang, Taipei (Taiwan) | ||
| Assigned to E-Pin Optical Industry Co., Ltd., Taipei (Taiwan) | ||
| Filed on Feb. 28, 2007, as Appl. No. 11/711,889. | ||
| Prior Publication US 2008/0204897 A1, Aug. 28, 2008 | ||
| Int. Cl. G02B 13/18 (2006.01); G02B 9/06 (2006.01) | ||
| U.S. Cl. 359—717 [359/794] | 4 Claims |
| 1. A two piece type optical lens, in order from the object side towards the image side, comprising:
an aperture stop;
a first lens element with positive refractive power that is a meniscus aspherical lens having a convex surface on an object
side, wherein the first lens element is made of molded glass;
a second lens element with positive refractive power that is a meniscus aspherical lens having a convex surface on an image
side, wherein the second lens element is made of molded glass;
an IR(infrared) cut-off filter; and
an image sensor arranged along an optical axis in order from the object side;
wherein following expressions are satisfied:
0.6f≤d <0.9f;
0.5<|R3|≤10f;
0.9<|f2|/|f1|<3;and
20≤Vd ≤85;
wherein f is an effective focal length of the optical lens, d is the distance between the object side of the first lens element
and 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.
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