Imaging lens system

Abstract

The present invention provides a compact imaging lens. The compact imaging lens comprises, from the object side to the image side, a diaphragm (2), a first positive meniscus lens (3) with a positive focal crescent shape which the convex surface of which facing the object side, and a second positive lens (4) the convex surface of which facing the image surface side, wherein following inequalities are satisfied 1.25>=L / fl>=0.8, 0.55>=f1 / f2>=0.2, 1.8>=f1 / fl>=1, 4>=f2 / fl>=1.5, 1>=d2 / d1>=0.5, 0.27>=d1 / fl>=0.1, 0.27 >=d3 / fl>=0.1 where, L: entire length of the lens system, Fl: focal distance of entire lens system, f1: focal distance of the first lens, f2: focal distance of the second lens, d1: center thickness of the first lens, d2: distance between the first lens and second lens on the optical axis, d3: center thickness of the second lens.

Description

technical field [0001] The present invention relates to an imaging lens, and more particularly to an imaging device for forming images of objects such as scenery and people on the imaging surface of a solid-state imaging element such as a CCD or CMOS disposed in a notebook computer, a videophone, a mobile phone, etc. An imaging lens consisting of two lenses that achieves compactness and weight reduction, improved optical performance, and improved manufacturability. Background technique [0002] In recent years, demand for video cameras using solid-state imaging elements such as CCDs and CMOSs, which are used in mobile phones, notebook computers, and video phones, for example, has increased significantly. Since such a camera must be arranged in a limited installation space, it is required to be small and lightweight. [0003] Accordingly, the imaging lens used for such a video camera is also required to be compact and lightweight. As such an imaging lens, a single-lens syste...

AI Technical Summary

Problems solved by technology

[0006] At this time, in the three-lens system, since various aberrations related to optical performance degradation can be effectively corrected, although extremely high optical performance can be obtained, the problem with the three-lens system is that due to the large number of parts, Therefore, it is difficult to achieve small size and light weight, and the high precision required for each component part also increases the manufacturing cost.

[0011] However, in recent years, for this type of imaging lens, in addition to the requirement of small size and light weight, there is an increasing demand for further improvement in optical performance. However, there is a problem that it is difficult to achieve a balance between small size and light weight and further improvement of optical performance, and it is also difficult to match the characteristics of the sensor (incident angle to the sensor)

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