Optical lens group

Abstract

The invention relates to an optical lens group. The object side surface of a first lens comprises a convex part near a circumference. A second lens has the negative refraction rate. The object side surface of a third lens comprises a concave part near the circumference. The image side surface of a fourth lens comprises a convex part near the circumference. The optical lens group meets the following relation: HFOV <= 25 DEG.; TTL <= 8mm; and TL/G23 <=4.5, wherein HFOV represent a half visual angle of the optical lens group, TTL represents a distance from the object side surface of the first lens to an imaging surface on the optical axis, TL represents a distance from the object side surface of the first lens to the image side surface of the fifth lens on the optical axis, and G23 represent the width of an air gap between the second lens and the third lens on the optical axis. Through controlling the concave and convex arrangement of each lens, the lens length is shortened in the condition of maintaining good optical performance.

Description

Technical field [0001] The present invention is related to an optical lens group, and particularly to an optical lens group using at least four lenses. Background technique [0002] In recent years, the popularization of portable electronic products such as mobile phones, digital cameras, tablet computers, and personal digital assistants (PDAs) has led to the rapid development of image modules including optical imaging lenses, module rear seat units, and image sensors. The thinner and lighter portable electronic products have also increased the demand for miniaturization of image modules. With technological advancement and size reduction, the optical lens set mounted in the image module also needs to be reduced in size, but the good optical performance of the optical lens set must also be considered. [0003] Since the size of the traditional miniature telescope lens exceeds 50mm and the number of apertures exceeds 4, it is obviously unable to meet the specifications of existing p...

AI Technical Summary

Problems solved by technology

[0003] Since the size of the traditional miniature telephoto lens exceeds 50mm and the number of f-stops exceeds 4, it is obviously unable to meet the specifications of existing portable electronic products. Good image quality and small lens space are required, and the improvement of the aperture size is also a subject that must be considered

However, the design of optical imaging lens is not simply to scale down the lens with good imaging quality to produce an optical lens group with both imaging quality and miniaturization. The design process involves material properties, and must also take into account the production and assembly yield. Due to practical problems in production, the technical difficulty of miniaturized lenses is obviously higher than that of traditional lenses

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