Imaging lens

Abstract

It is to provide an imaging lens that can sufficiently handle the demands for reduction in size and weight and further improvement in the optical performance to improve the production. The imaging lens comprises, in order from the object towards the image side , a diaphragm, a first lens which is a meniscus lens, the convex surface of which faces the object, and a second lens which is a lens having positive power, the convex surface of which faces the image, wherein conditions expressed by each of following inequalities (1)-(6) are to be satisfied; 1.25 L / fl 0.8, 1 f 1 / f 2 0.2, 1.8 f 1 / fl 1, 0.5>d 2 / d 1 0.2, 0.35 d 1 / fl 0.1, and 0.27 d 3 / fl 0.1 (where, L: entire length of the lens system, fl: focal distance of the entire lens system, f 1 : focal distance of the first lens, f 2 : focal distance of the second lens, d 1 : center thickness of the first lens, d 2 : space between the first lens and the second lens on the optical axis, and d 3 : center thickness of the second lens).

Description

technical field [0001] The present invention relates to an imaging lens, in particular to an imaging device used for imaging objects such as scenery or people on the imaging surface of a solid-state imaging element such as a CCD or CMOS mounted on a portable computer, a TV phone, a mobile phone, etc. An imaging lens with a two-element lens structure that realizes compactness and weight reduction, improved optical performance, and improved manufacturability. Background technique [0002] In recent years, the demand for cameras using solid-state imaging elements such as CCD and CMOS for mounting in mobile phones, portable computers, and video phones has been remarkably increasing. Since such a camera needs to be installed in a limited installation space, it is required to be small and lightweight. [0003] For this reason, an imaging lens used in such a camera is also required to be compact and lightweight, and conventionally, a lens system using a single lens has been used f...

AI Technical Summary

Problems solved by technology

[0011] However, in recent years, in such an imaging lens, there has been an increasing demand for further improvement in optical performance on the basis of small size and weight reduction. However, as in the imaging lenses described in Patent Documents 1 and 2, the In the structure of the iris diaphragm, it is difficult to achieve further improvement in optical performance while reducing size and weight, and there is a problem that it is difficult to combine with the characteristics of the sensor (incident angle to the sensor)

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