CN201917927U

CN201917927U - Surface type optical fingerprint acquisition instrument

Info

Publication number: CN201917927U
Application number: CN2011200180171U
Authority: CN
Inventors: 李扬渊; 汪镜; 方丽君
Original assignee: CHENGDU FINCHOS ELECTRON Co Ltd
Current assignee: CHENGDU FINCHOS ELECTRON Co Ltd
Priority date: 2011-01-20
Filing date: 2011-01-20
Publication date: 2011-08-03
Anticipated expiration: 2021-01-20

Abstract

The utility model provides a surface type optical fingerprint acquisition instrument comprising a casing, a collection board, an imaging device and a circuit board. The surface type optical fingerprint acquisition instrument is characterized in that the collection board at least comprises a transparent contact layer and a transparent luminous layer positioned below the transparent contact layer; the transparent luminous layer comprises an acquisition luminous area and a display luminous area; both the acquisition luminous area and the display luminous area are electrically connected with the circuit board; the acquisition luminous area is ring-shaped and is positioned at the edge of an effective acquisition area; and an imaging device is positioned right below the collection board. The surface type optical fingerprint acquisition instrument provided by the utility model eliminates trapezoidal distortion of finger-print images, is surface-shaped, and has small size, lower product cost and expanded application range.

Description

A kind of type optical fingerprint acquisition instrument

Technical field

The utility model relates to optical fingerprint acquisition instrument, relates in particular to a kind of type optical fingerprint acquisition instrument.

Background technology

Optical fingerprint acquisition instrument is a widely used fingerprint acquisition device in the existing fingerprint recognition system, it utilize light on the interface because of when contact finger the crestal line valley line the optical difference that causes of difference form image and gather.

The optical fingerprint acquisition instrument collection be fingerprint top layer texture image, specific irradiate light forms reflection ray to the finger surface, because the crestal line of fingerprint and valley line is concavo-convex different, the amount that forms reflection ray is also just different, and reflection ray is captured as picture through imaging device again.

Because the harvester of traditional optical fingerprint acquisition instrument adopts prism usually, its fingerprint collecting face is different with distance (light path) between the imaging surface, therefore with the position relative real image of (imaging surface position) fingerprint image of phasing final image distortion has taken place in formation, the fingerprint image that causes being collected will be difficult for being identified, and this distortion is called trapezoidal distortion.

In order to solve the trapezoidal distortion problem of fingerprint image, application number is the imaging optical system that 98215867 patent of invention has adopted telecentric beam path, by being used for from a collector lens and a correcting lens of the fingerprint image that converges the prism projection or proofreading and correct that prism is combined to be proofreaied and correct the trapezoidal distortion and the astigmatism of image.Yet said method is not to solve pattern distortion from basic reason, because separated installations such as collector lens, image rectification prism can increase the size of product and the complicacy of light path thus, finally causes the increase of manufacturing cost and the reduction of production efficiency.

Summary of the invention

For solving the problems of the technologies described above, the utility model provides a kind of type optical fingerprint acquisition instrument, comprises shell, collection plate, imaging device and circuit board, it is characterized in that, described collection plate comprises a transparent contact layer and a transparent luminescent layer at least;

Described transparent luminescent layer is positioned at transparent contact layer below;

Described transparent luminescent layer comprises to be gathered light-emitting zone and shows light-emitting zone, and described collection light-emitting zone and demonstration light-emitting zone electrically connect with circuit board respectively;

Described collection light-emitting zone is an annular, is positioned at effective pickup area edge;

Described imaging device be positioned at collection plate under.

Described collection plate also has a protective clear layer, and described protective clear layer is positioned at the below of transparent luminescent layer.

Be fixed on the shell around the described collection plate; Described circuit board is fixed on outer casing bottom, constitutes confined space with collection plate and shell.

Described imaging device is made up of lens combination and imaging surface, and described imaging device is installed on the circuit board; The center three of the center of described light source, the primary optical axis of lens combination and imaging surface is coaxial.

The utility model utilizes the acquisition elements of collection plate as fingerprint image, imaging device be positioned at collection plate under, feasible distance (light path) unanimity from collection face to imaging surface, thereby eliminated the fingerprint image trapezoidal distortion, the utility model makes entire product be tending towards the face typeization, size is little, has reduced cost of products and has enlarged usable range.

Description of drawings

Fig. 1 is a structural diagrams intention of the present utility model;

Fig. 2 is the collection plate structural representation of the utility model embodiment;

Fig. 3 is the structural representation of the transparent luminescent layer of the utility model embodiment; Wherein Fig. 3-a is the front view of the transparent luminescent layer of embodiment, and Fig. 3-b is the vertical view of the transparent luminescent layer of embodiment;

Fig. 4 is the local index path of the utility model embodiment.

Embodiment

Preferred embodiment of the present utility model is described with reference to the accompanying drawings, and specific embodiment described herein is only in order to explaining the utility model, and is not used in qualification the utility model.

Specific embodiment:

Referring to Fig. 1, Fig. 2, Fig. 3, Fig. 4, a kind of type optical fingerprint acquisition instrument of the present utility model comprises: shell 1, collection plate 2, imaging device 3 and circuit board 4.

Collection plate 2 comprises transparent contact layer 21 and transparent luminescent layer 22 at least, and transparent contact layer 21 is used for directly contacting with finger, and transparent luminescent layer 22 is positioned at the below of transparent contact layer 21.

Transparent luminescent layer 22 comprises to be gathered light-emitting zone A and shows light-emitting zone B, gathers light-emitting zone A and shows that light-emitting zone B electrically connects with circuit board 4 respectively; The collection light-emitting zone A of transparent luminescent layer 22 is an annular, is positioned at effective pickup area edge (as shown in Figure 3) of transparent contact layer 21.

Collection plate 2 also has a protective clear layer 23, and protective clear layer 23 is positioned at the below of transparent luminescent layer 22, is used to protect collection plate 2 internal materials not to be damaged.

Circuit board 4 is fixed on shell 1 bottom, is used for installing device and circuit and connects, and constitutes confined space with collection plate 2 and shell 1.Imaging device 3 is made up of lens combination 31 and imaging surface 32, imaging device 3 be positioned at collection plate 2 under, and be installed on the circuit board 4, be used to receive from the light of the band finger print information of collection plate 2 outgoing and form fingerprint image; The center three of the primary optical axis of the center of described collection plate 2, lens combination 31 and imaging surface 32 is coaxial.Described imaging surface 32 is a semiconductor imaging sensor array, and described semiconductor imaging sensor is ccd sensor or cmos sensor.

When the collection light-emitting zone A of transparent luminescent layer 22 energising, when showing light-emitting zone B no power, the face type optical fingerprint acquisition instrument that the utility model provides carries out fingerprint collecting: as shown in Figure 4, the light that collection light-emitting zone A sends is in two surperficial experiences total internal reflection up and down of collection plate 2 inside, the light that is reflected to the crestal line place on the transparent contact layer 21 has changed total reflection condition because of the tight contact of crestal line, a part is absorbed by the finger coupling, diffuse reflection takes place in a part, and the reflection ray that transmits from collection plate 2 belows is captured as picture by imaging device 3; Because the fingerprint valley line does not closely contact with transparent contact layer 21, total reflection condition is still set up, the light at valley line place will be in the continuous total reflection of collection plate 2 inner upper and lower surfaces, light can not transmit collection plate 2, therefore the light at valley line place can't be caught by imaging device 3, incide the light quantity of imaging device 3 from the fingerprint valley line like this and come by difference, thereby obtain a width of cloth crestal line place darker fingerprint image in brighter valley line place with the light quantity that incides imaging device 3 from fingerprint ridge line.

When the fingerprint collecting end, the collection light-emitting zone A outage of transparent luminescent layer 22 when showing light-emitting zone B energising, shows that light-emitting zone B shows the picture shape that this is regional by the light that sends, thereby feeds back to visualized result of user.For example when fingerprint comparison was incorrect, collection plate 2 showed one " * ", if comparison is correct, can show on collection plate 2 one " √ ".

Those skilled in the art can also carry out various modifications to above content under the condition that does not break away from the definite spirit and scope of the present utility model of claims.Therefore scope of the present utility model is not limited in above explanation, but determine by the scope of claims.

Claims

1. a face type optical fingerprint acquisition instrument comprises shell, collection plate, imaging device and circuit board, it is characterized in that, described collection plate comprises a transparent contact layer and a transparent luminescent layer at least;

Described imaging device be positioned at collection plate under.

2. a kind of type optical fingerprint acquisition instrument according to claim 1 is characterized in that described collection plate also has a protective clear layer, and described protective clear layer is positioned at the below of transparent luminescent layer.

3. a kind of type optical fingerprint acquisition instrument according to claim 1 is characterized in that, is fixed on the shell around the described collection plate; Described circuit board is fixed on outer casing bottom, constitutes confined space with collection plate and shell.

4. a kind of type optical fingerprint acquisition instrument according to claim 1 is characterized in that described imaging device is made up of lens combination and imaging surface, and described imaging device is installed on the circuit board; The center three of the center of described light source, the primary optical axis of lens combination and imaging surface is coaxial.