Optical image capturing lens system

Abstract

This invention provides an optical image capturing lens system comprising: a negative first lens element having a convex object-side surface and a concave image-side surface at the paraxial region; a positive second lens element; a negative third lens element; a positive fourth lens element having a convex image-side surface at the paraxial region; and a negative plastic fifth lens element having a convex object-side surface at the paraxial region as well as a concave at the paraxial region and convex at the peripheral region image-side surface, at least one of the object-side and image-side surfaces being aspheric. The optical image capturing lens system of the present invention effectively increases the angle of view to a proper range and suppresses the distortion. In addition, the present invention has a tighter arrangement of the lens elements and a smaller back focal length, and therefore is more appropriate for the compact device.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 101127138 filed in Taiwan (R.O.C.) on Jul. 27, 2012, the entire contents of which are hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to an optical image capturing lens system, and more particularly, to a compact optical image capturing lens system used in electronic products.[0004]2. Description of the Prior Art[0005]The demand for compact imaging lens assembly has grown in recent years as the popularity of portable electronic products with the photographing function has increased. The sensor of a general photographing camera is none other than CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor Sensor). Furthermore, as advanced semiconductor manufacturing technology has allowed the pixel size of sensors to be reduced, and the current elec...

AI Technical Summary

Benefits of technology

The present invention is an optical image capturing lens system that allows for a wider angle of view and reduces distortion while maintaining a compact device. The lens elements are arranged in a tight manner and have small back focal lengths, making it suitable for a wide-angle lens system. The first lens element has negative refractive power, the second lens element has positive refractive power, and the third lens element has negative refractive power, which effectively corrects astigmatism. The fourth lens element has positive refractive power, which reduces the sensitivity of the system and allows for a smaller back focal length. The fifth lens element has negative refractive power, which corrects astigmatism and reduces the angle at which light projects onto the image sensor. Overall, the lens system provides a wide field of view with minimal distortion and improved sensing efficiency.

Problems solved by technology

While such arrangement facilitates the enlargement of the field of view, the aberration correction of the optical system is ineffective due to the inclusion of only one lens element in the rear lens group.

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