CN1146355C - Three-sided fingerprint collecting method and device - Google Patents

Abstract

The present invention discloses a three-surface fingerprint collection method and a device. The device is characterized in that a main light path optical system is used to make fingerprint images formed in a main light path sensor, and the fingerprint images are collected and converted into electric signals; the device is provided with an auxiliary light path optical system and an auxiliary light path sensor, wherein the auxiliary light path optical system is used to make fingerprints imaged in the auxiliary light path sensor and converts finger images into finger position information; the finger position information is sent out to a motor driving circuit which controls a motor to move according to the finger position information so as to control the displacement of the main light path sensor and the main light path optical system. The present invention can achieve automatic tracking of finger movement in the process of collection.

Description

Three-sided fingerprint collecting method and device

The present invention relates to a kind of three-sided fingerprint collecting method and device.

Refer to that singly three-sided fingerprint (rolling fingerprint) collection is the basic demand to fingerprint collecting in criminal investigation is used of fingerprint recognition technology.For satisfy criminal investigation use in to the fingerprint image acquisition scope and gather requirement such as density, alertly at present adopt linear charge-coupled array (CCD) as image sensor with fingerprint picked-up instrument.Generate two-dimentional finger print image by the self-scanning of charge-coupled image sensor and the subscan that produces by machine driving.In gathering the three-sided fingerprint process, finger roll and subscan particularly important to the generation final image synchronously.

Purpose of the present invention is exactly in order to overcome the above problems, and a kind of three-sided fingerprint collecting method and device are provided, and realizes the synchronous of finger roll and subscan.

The present invention realizes that the scheme of above-mentioned purpose comprises three-sided fingerprint collecting method and harvester.Described three-sided fingerprint collecting method is: utilize the main optical path optical system that finger print image is imaged onto on the main optical path pick off, the main optical path pick off is gathered finger print image, changes into the signal of telecommunication; It is characterized in that: outside main optical path, auxiliary optical path optical system and auxiliary optical path pick off are set, utilize the auxiliary optical path optical system with fingerprint imaging to the auxiliary optical path pick off, the auxiliary optical path pick off is surveyed the finger picture inversion and is become finger position information; With this direct information motor-drive circuit, motor-drive circuit is according to the motion of finger position information control motor, and after the drive mechanism transmission, the displacement of control main optical path pick off and main optical path optical system, make motor and finger roll synchronous, meanwhile, the corresponding fingerprint image of main optical path collection.

Described three-sided fingerprint harvester comprises acquisition window, main optical path optical system, main optical path pick off, the finger print image in the acquisition window through the main optical path optical system imaging in the main optical path pick off; It is characterized in that: outside main optical path, be provided with auxiliary optical path optical system and auxiliary optical path pick off, finger image in the acquisition window through the auxiliary optical path optical system imaging in the auxiliary optical path pick off, the auxiliary optical path pick off is electrically connected with motor-drive circuit through signal processing unit, logic control element successively, motor-drive circuit links to each other with motor, and motor links to each other with drive mechanism.

Owing to adopted above scheme, promptly outside main optical path, auxiliary optical path optical system and auxiliary optical path pick off are set also, utilize these devices at the light path up-sampling, to realize synchronous tracking to finger motion.Above-mentioned synchronous tracking technology can reach the optimum state that people, machine coordinate, and is complete, obtain the three-sided fingerprint image without distortion.

Fig. 1 is a principle of the invention sketch map.

Fig. 2 is an embodiment of the invention light path sketch map.

Fig. 3 is an embodiment of the invention circuit diagram.

Fig. 4 is that the embodiment of the invention is followed the tracks of the collecting flowchart sketch map.

Also the present invention is described in further detail in conjunction with the accompanying drawings below by specific embodiment.

Embodiment one: see Fig. 1, be depicted as a kind of three-sided fingerprint collecting method, utilize main optical path optical system 5 that finger print image is imaged onto on the main optical path pick off 6,6 pairs of finger print images of main optical path pick off are gathered, and change into the signal of telecommunication; It is characterized in that: outside main optical path, auxiliary optical path optical system 2 and auxiliary optical path pick off 3 are set, utilize auxiliary optical path optical system 2 with fingerprint imaging to auxiliary optical path pick off 3, auxiliary optical path pick off 3 is surveyed the finger image and is also converted finger position information to; With this direct information motor-drive circuit 7, motor-drive circuit 7 is controlled the motion of motor 8 according to finger position information, and after drive mechanism 9 transmissions, controls the position of main optical path pick off 6 and main optical path optical system 5.

According to said method, three-sided fingerprint harvester of the present invention comprises acquisition window 1, main optical path optical system 5, main optical path pick off 6, and the finger print image in the acquisition window 1 images in main optical path pick off 6 through main optical path optical system 5; It is characterized in that: outside main optical path, be provided with auxiliary optical path optical system 2 and auxiliary optical path pick off 3, finger image in the acquisition window 1 images in auxiliary optical path pick off 3 through auxiliary optical path optical system 2, auxiliary optical path pick off 3 is electrically connected with motor-drive circuit 7, motor-drive circuit 7 links to each other with motor 8, and motor 8 links to each other with drive mechanism 9.

Fig. 2 is the light path sketch map of one embodiment of the invention.In this example, described acquisition window 1 is a Collection prism, and described main optical path pick off 6 and auxiliary optical path pick off 3 are linear charge-coupled array.

Main optical path is used to gather finger print image, and auxiliary optical path passes to circuit for controlling motor with the positional information in the finger roll process, makes motor and finger roll synchronous operation.Meanwhile, main optical path is gathered the fingerprint image of relevant position.

The fingerprint collecting scope is 40mm * 40mm.Wherein 40mm * 30mm is often put the zone for finger, and the finger position acquisition sensor is also selected linear charge-coupled array for use, and its photosensitive region length is 8.114mm, with the parallel placement of direction of the subscan of main optical path.In optical system, the pickup area of this 40mm * 30mm is mapped to the bright band of 8mm * 2.5mm.Guaranteeing this bright band and auxiliary optical path pick off 3 by mechanical micro-adjusting mechanism---charge-coupled image sensor coincide.When finger rolled on the wide acquisition window of 40mm from right to left, its imaging bright spot moved in the photosensitive region of charge-coupled image sensor from left to right.This information passes to circuit for controlling motor, make the subscan and the finger roll of the main optical path of motor traction start synchronously, move, stop, so the main optical path synchronous acquisition is to the fingerprint image of relevant position.

When finger when acquisition window rolls, with this converting optical signals, and image in the finger position acquisition sensor by auxiliary optical path, and positional information passed to Computer Processing.The finger roll process is resolved into a series of actions, computer just obtains a series of finger position information, these information have formed finger motion locus, according to this movement locus, can control the angular displacement of subscan in real time, subscan and finger position are consistent, thereby have reached the purpose of synchronous tracking.

Its circuit diagram as shown in Figure 3.It comprises: 1) signal processing unit, comprise be used for the signal that charge-coupled image sensor uses carry out analog-to-digital A/D changer U1 (this example TLC5510), in order to the memorizer U2 (this example HM62128) of stored charge coupled apparatus signal; 2) logic control element, (this example is carried out the decoder U4 (this example GAL20V8) of address decoding with (XC9572), when being used for the I/O operation to comprise the logic programmable chip U3 that is used for whole tracking card logic control.

The effect of decoder U4 (GAL20V8) is used for controlling reads and writes charge-coupled image sensor.At first pass through decoder U4, and the control of process logic programmable chip U3, charge-coupled image sensor is driven.The signal that charge-coupled image sensor is passed back immediately is stored among the memorizer U2, when computer needs data to cross the conversion of U1, just fetch data by isa bus, analyzing and processing in addition, and the control of U1, U2 and charge-coupled image sensor is all finished by logic programmable chip U3.The flow chart of its tracking sampling as shown in Figure 4.

The implication of each symbol is as follows among Fig. 3: WE: write signal CE: chip selection signal; D0-D7: number The number of it is believed that; A0-A7: address signal; OE: enable signal; I/O: I/O end; Iout1, Iout2: output signal end; IOW: input and output write signal; IOR: input and output read signal; AIN: The analog signal of input; CLK: clock signal; SI: output starting impulse; Vcc: power end; Ref: datum; Refm: half datum; C2, C5: capacitor.

Claims (4)

1, a kind of three-sided fingerprint collecting method utilizes main optical path optical system (5) that finger print image is imaged onto on the main optical path pick off (6), and main optical path pick off (6) is gathered finger print image, changes into the signal of telecommunication; It is characterized in that: outside main optical path, auxiliary optical path optical system (2) and auxiliary optical path pick off (3) are set, utilize auxiliary optical path optical system (2) that fingerprint imaging is arrived on the auxiliary optical path pick off (3), auxiliary optical path pick off (3) is surveyed the finger picture inversion and is become finger position information; With this direct information motor-drive circuit (7), motor-drive circuit (7) is according to the motion of finger position information control motor (8), and after drive mechanism (9) transmission, the displacement of control main optical path pick off (6) and main optical path optical system (5) makes motor and finger roll synchronous; Meanwhile, the corresponding fingerprint image of main optical path collection.

2, three-sided fingerprint collecting method as claimed in claim 1 is characterized in that: auxiliary optical path optical system (2) is mapped to belt-like zone with the fingerprint collecting zone, and the position of bright band adjusted to auxiliary optical path pick off (3) matches; The length of the photosensitive region of auxiliary optical path pick off (3) just in time drops on the auxiliary optical path pick off (3) bright band more than or equal to the length of bright band.

3, a kind of three-sided fingerprint harvester comprises acquisition window (1), main optical path optical system (5), main optical path pick off (6), and the finger print image in the acquisition window (1) images in main optical path pick off (6) through main optical path optical system (5); It is characterized in that: outside main optical path, be provided with auxiliary optical path optical system (2) and auxiliary optical path pick off (3), finger image in the acquisition window (1) images in auxiliary optical path pick off (3) through auxiliary optical path optical system (2), auxiliary optical path pick off (3) is electrically connected with motor-drive circuit (7) through signal processing unit, logic control element successively, motor-drive circuit (7) links to each other with motor (8), and motor (8) links to each other with drive mechanism (9).

4, fingerprint acquisition device as claimed in claim 3 is characterized in that: described acquisition window (1) is a Collection prism, and described main optical path pick off (6) and auxiliary optical path pick off (3) are linear charge-coupled array.

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