Imaging lens, iris imaging module and iris identification device

Abstract

The invention discloses an imaging lens, an iris imaging module and an iris identification device, and belongs to the field of biological identification. From front to back of a light incidence direction, the imaging lens sequentially comprises: a first lens, wherein the first lens is a convex-concave lens with positive power, the front surface is a convex surface, and the back surface is a concave surface; a second lens, wherein the second lens is a convex-concave lens with negative power, the front surface is a convex surface, and the back surface is a concave surface; and a third lens, wherein the third is a convex-concave lens with positive power, the front surface is a convex surface, and the back surface is a concave surface. The imaging lens provided by the invention is good in imaging quality, simple in structure and low in cost.

Description

technical field [0001] The invention relates to the field of biological identification, in particular to an imaging lens, an iris imaging module and an iris identification device. Background technique [0002] Iris recognition belongs to the field of biometrics. It is a biometric technology based on the iris of the eye. This technology authenticates the user's identity by processing the iris texture information in an area smaller than 10mm. Compared with other biometric technologies, iris recognition is unique and stable. It has become the most accurate identification technology at present. The difficulty in realizing iris recognition technology lies in how to collect clear and high-quality irises picture like, thus collecting the iris picture The optical system of the image becomes the key of the iris recognition device. [0003] The existing iris collection optical system can be divided into: zoom optical system and fixed focus optical system, among which the zoom optic...

AI Technical Summary

Problems solved by technology

[0003] The existing iris collection optical system can be divided into: zoom optical system and fixed focus optical system, among which the zoom optical system is large in size, complex in structure, high in cost and difficult to assemble, such as: the patent CN200810071474. The compensation zoom lens is composed of more than a dozen lenses; the fixed-focus optical system has simple structure, low cost and convenient installation, such as: the iris recognition device in Japanese patent JP2004-167046, its acquisition lens is composed of two lenses and filters, but The system has poor imaging quality, large spherical aberration and other aberrations, and less freedom in optical design; US invention patent 20090161069A1 improves the optical structure in the above patent by replacing the filter with a rotationally symmetrical aspheric mirror , that is, a three-piece system, which improves the imaging quality better, but the use of aspheric mirrors increases the manufacturing cost. Therefore, a fixed-focus optical system with good imaging quality, simple structure and low cost has become the focus of current research.

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