Iris recognition optical system having short total length

Abstract

An iris recognition optical system having short total length includes first lens having positive diopter and second lens having negative diopter and axially disposed in alignment with first lens. The first lens includes second reflecting surface located on object side around optical axis, first transmissive surface with concave curvature located on object side around second reflecting surface and exhibiting vertical profile relative to said optical axis, second transmissive surface located on image side around optical axis, and first reflecting surface located on image side around second transmissive surface. As first lens is configured to provide two opposite reflecting surfaces, focal length of system can be greatly shortened, and therefore, the system can be installed in cell phone, smart phone, tablet computer, notebook or any other low-profile mobile electronic device, allowing product user to easily and stably get iris images from a distance of about 300 mm.

Description

technical field [0001] The present invention relates to an optical system for short-distance iris recognition, which utilizes a lens having two reflective surfaces, so that its focal length is extremely shortened, so it can be stably used in thinned devices such as mobile phones, smart phones, tablet computers, and notebook computers. On small portable electronic products, to identify the user's iris. Background technique [0002] In recent years, centering on access control systems, computer security systems, etc., biometric identification technology that widely uses human body characteristics to confirm personal identity has gradually become popular. The application field of biometric identification technology has gradually expanded from fingerprint identification as the mainstream in the past to recent Applications such as iris recognition, voice recognition or vein recognition. [0003] In particular, the iris surrounding the entire pupil of the eye can be identified an...

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Problems solved by technology

[0013] But the biconvex spherical lens (2A) thickness in the patent document 1 is 2.92mm, the thickness of the biconcave spherical lens (3A) is 3.00mm, and the distance between the biconcave spherical lens (3A) and the visible light filter (4A) is 2.45mm, the thickness of the visible light filter (4A) is 3.00mm, obviously, the total length of the entire optical system has exceeded 20mm by a lot

[0014] Therefore, the optical system for iris recognition as in Patent Document 1 is not suitable for thin and small electronic products such as smart phones.

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