CN2713494Y

CN2713494Y - Fingerprint recognizer

Info

Publication number: CN2713494Y
Application number: CN 200420046177
Authority: CN
Inventors: 闵瑜
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-19
Filing date: 2004-05-19
Publication date: 2005-07-27
Anticipated expiration: 2014-05-19

Abstract

The utility model discloses optic fingerprint identification equipment which comprises a triple prism 1, a frame component 2, a lens group 3, a CMOS image sensor 4 and a luminaire 5, wherein the triple prism 1 is an equicrural prism and two equal angles are 50 DEG. The triple prism 1, the luminaire 5, the lens group 3 and the CMOS image sensor 4 are arranged in the frame component 2 in turn. The CMOS image sensor 4 is placed aslant, and the imaging surface and the target face are superposed. The fingerprint image is formed on the CMOS image sensor through the lens group under the refraction and reflex actions of the triple prism to light. Therefore, the fingerprint identification is conducted.

Description

Fingerprint identification device

Technical field

The utility model belongs to optical technical field, particularly a kind of fingerprint identifying optical system.

Background technology

Continuous development along with science and technology, the identification of personal identification is also more important, fingerprint has uniqueness and unchangeability, fingerprint identification technology is easy to use, safe and reliable, be widely used in all trades and professions, as fingerprint gate lock, fingerprint gate guard control system, ecommerce, bank savings, social insurance etc.Optical fingerprint acquisition instrument of the prior art adopts the increase optical element to correct distortion more, its structure more complicated, and volume is bigger.

Summary of the invention

The purpose of this utility model provides a kind of novel optical finger print recognition device, and volume is little, and is simple in structure, easy to use, and production cost is low.

In order to achieve the above object, the technical solution of the utility model is as follows:

A kind of optical finger print recognition device comprises prism 1, frame assembly 2, lens combination 3, cmos image sensor 4, light source 5; Wherein prism 1 is the isosceles prism, and two isogonism angles are 50 degree, and prism 1, light source 5, lens combination 3, cmos image sensor 4 place frame assembly 2 successively, and cmos image sensor 4 tilts to place, and imaging surface and target surface coincide.

Owing to adopted said structure, can fingerprint image be imaged onto on the cmos image sensor through lens combination, thereby carry out fingerprint recognition by the refraction and the reflex of prism to light.

Description of drawings

Fig. 1 is the utility model perspective view;

Fig. 2 is the isosceles prism synoptic diagram;

Fig. 3 is the utility model assembling synoptic diagram;

Fig. 4 is the utility model index path.

Embodiment

Below in conjunction with drawings and Examples the utility model is described in further detail:

A kind of optical finger print recognition device comprises prism 1, frame assembly 2, lens combination 3, cmos image sensor 4, light source 5; As shown in Figure 2, prism 1 is the isosceles prism, and two isogonism angles are 50 degree; As shown in Figure 3, prism 1, light source 5, lens combination 3, cmos image sensor 4 place frame assembly 2 successively.Light source 5 is positioned at 11 of prism 1, tested finger is pressed on 13 of prism 1, because finger print is raised in finger surface, 13 of fingerprint and prism 1 closely contact, and have destroyed the condition of total reflection, and a part of incident light will be lost by finger, remaining part light reflection, go out from 12 transmissions of prism 1, lens combination 3 to cmos image sensor 4, and is shown as the low light level with the photoimaging of each point reflection on the fingerprint.And the recess between the fingerprint projection, its refractive index is less, total reflection can take place in incident light herein, so the each point of recess is shown as high light on cmos image sensor, like this, the catoptrical power of each point on the tested finger surface that shows from cmos image sensor just can obtain fingerprint lines clearly.

As shown in Figure 4, because finger print imaging in prism 1 is the virtual image, the plane at its place and optical axis are off plumbs, scioptics group 3 back imagings also with the optical axis out of plumb, cmos image sensor 4 is tilted to place, and the target surface and the image planes that transfer to cmos image sensor 4 coincide, and reduce distortion, and image is more clear.

Claims

1, a kind of optical finger print recognition device is characterized in that: comprise prism (1), frame assembly (2), lens combination (3), cmos image sensor (4), light source (5); Prism (1), light source (5), lens combination (3), cmos image sensor (4) place frame assembly (2) successively.

2, optical finger print recognition device according to claim 1 is characterized in that described prism (1) is the isosceles prisms, and two isogonism angles are 50 degree.

3, optical finger print recognition device according to claim 1 is characterized in that described cmos image sensor (4) tilt to place, and imaging surface and target surface coincide.