Optical Image Capturing System

Abstract

An optical image capturing system, sequentially including a first lens element, a second lens element, a third lens element and a fourth lens element from an object side to an image side, is disclosed. The first lens element has positive refractive power. The second lens element, the third lens element and the fourth lens element have refractive power respectively. At least one of the image side surface and the object side surface of each of the four lens elements are aspheric. The optical lens elements can increase aperture value and improve the imagining quality for use in compact cameras.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of Taiwan Patent Application No. 104112454, filed on Apr. 17, 2015, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present disclosure relates to an optical image capturing system, and more particularly to a compact optical image capturing system which can be applied to electronic products.[0004]2. Description of the Related Art[0005]In recent years, with the rise of portable electronic devices having camera functionalities, the demand for an optical image capturing system is raised gradually. The image sensing device of ordinary photographing camera is commonly selected from charge coupled device (CCD) or complementary metal-oxide semiconductor sensor (CMOS Sensor). In addition, as advanced semiconductor manufacturing technology enables the minimization of pixel siz...

AI Technical Summary

Benefits of technology

[0022]The optical image capturing system described above is applicable to the demand of video recording with above millions or ten millions-pixels (e.g. 4K2K or called UHD, QHD) and leads to a good imaging quality.

[0023]The height of optical system (HOS) may be reduced to achieve the minimization of the optical image capturing system when the absolute value of f1 is larger than f4 (|f1|>f4).

[0024]When |f2|+|f3|>|f1|+|f4| is satisfied with above relations, at least one of the second through third lens elements may have weak positive refractive power or weak negative refractive power. The weak refractive power indicates that an absolute value of the focal length of a specific lens element is greater than 10. When at least one of the second through third lens elements has the weak positive refractive power, the positive refractive power of the first lens element can be shared, such that the unnecessary aberration will not appear too early. On the contrary, when at least one of the second through third lens elements has the weak negative refractive power, the aberration of the optical image capturing system can be corrected and fine tuned.

[0025]The fourth lens element may have negative refractive power and a concave image-side surface. Hereby, the back focal length is reduced for keeping the miniaturization, to miniaturize the lens element effectively. In addition, at least one of the object-side surface and the image-side surface of the fourth lens element may have at least one inflection point, such that the angle of incident with incoming light from an off-axis view field can be suppressed effectively and the aberration in the off-axis view field can be corrected further.

Problems solved by technology

But the optical image capturing system with the large aperture design often produces more aberration resulting in the deterioration of quality in peripherical image formation and difficulties of manufacturing, and the optical image capturing system with wide view angle design increases distortion rate in image formation, thus the optical image capturing system in prior arts cannot meet the requirement of the higher order camera lens module.

Therefore, how to effectively increase quantity of incoming light and view angle of the optical lenses, not only further improves total pixels and imaging quality for the image formation, but also considers the equity design of the miniaturized optical lenses, becomes a quite important issue.

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