FINGERPRINT IDENTIFICATION METHOD AND DEVICE THEREOF

• US 20170323139A1
• Filed: 07/13/2016
• Published: 11/09/2017
• Est. Priority Date: 08/25/2015
• Status: Active Grant

• Current Assignee: Gingy Technology Inc.
• Original Assignee: Gingy Technology Inc.
• Inventors: Wu, Jen-Chieh, Hung, Chun-Lang
• Granted Patent: US 9,977,947 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths

Abstract

A fingerprint identification method is provided. The method includes steps as follows: having a finger press on a photoelectronic sensor module; respectively emitting an invisible light beam reflected to a photoelectronic sensor module after passing through the finger and a visible light beam reflected to the photoelectronic sensor module via a surface of the finger; generating, by the photoelectronic sensor module, photocurrent signals based on the visible light beam and the invisible light beam; respectively generating, by an analog/digital converter module, a first digital signal and a second digital signal based on the photocurrent signals; and outputting, by a processor module, the first digital signal as a gray-scale fingerprint image and a second digital signal as a colored fingerprint image. The invention also provides a fingerprint identification device performing the fingerprint identification method.

Claims

1. A fingerprint identification method, comprising:

placing a finger on a photoelectronic sensor module;

emitting an invisible light beam toward the finger by a first light emitting element and emitting a visible light beam toward the finger by a second light emitting element;

reflecting the invisible light beam to the photoelectronic sensor module after the invisible light beam passes through the finger, such that the photoelectronic sensor module receives at least one invisible light intensity signal of the invisible light beam, and reflecting the visible light beam to the photoelectronic sensor module via a surface of the finger, such that the photoelectronic sensor module receives at least one visible light intensity signal of the visible light beam;

generating at least one invisible light photocurrent signal based on the invisible light intensity signal by the photoelectronic sensor module, generating at least one visible light photocurrent signal based on the visible light intensity signal by the photoelectronic sensor module, and transmitting the invisible light photocurrent signal and the visible light photocurrent signal respectively to an analog/digital converter module by the photoelectronic sensor module;

generating at least one first digital signal based on the invisible light photocurrent signal by the analog/digital converter module, generating at least one second digital signal based on the visible light photocurrent signal by the analog/digital converter module, and transmitting the first digital signal and the second digital signal respectively to a processor module by the analog/digital converter module; and

generating a gray-scale fingerprint image based on the first digital signal by the processor module, generating a colored fingerprint image based on the second digital signal by the processor module, and perfoiiiiing identification based on the gray-scale fingerprint image and the colored fingerprint image.

2. The fingerprint identification method as claimed in claim 1, wherein the processor module comprises an analyzing program, a converting program and a validating program, and the step of performing identification based on the colored fingerprint image further comprises:

executing the analyzing program to analyze the colored fingerprint image with a first color model, thereby obtaining first chromaticity coordinates corresponding to the colored fingerprint image;

executing the converting program to convert the first chromaticity coordinates into second chromaticity coordinates with a second color model;

executing the validating program and comparing whether the second chromaticity coordinates meet a predetermined second skin color threshold;

determining that a fingerprint of the finger is a real fingerprint if the second chromaticity coordinates meet the second skin color threshold; and

determining that a fingerprint of the finger is a forged fingerprint if the second chromaticity coordinates do not meet the second skin color threshold.

3. The fingerprint identification method as claimed in claim 2, wherein the fingerprint image is divided into a plurality of sub-images, and the sub-images are respectively and sequentially transmitted to the analyzing program for an analyzing process.

4. The fingerprint identification method as claimed in claim 2, wherein the step of analyzing the colored fingerprint image with the first color model further comprises:

setting the first color model to be an RGB color model;

obtaining the corresponding first chromaticity coordinates based on the RGB color model, obtaining a red wavelength curve, a green wavelength curve and a blue wavelength curve based on the first chromaticity coordinates;

determining whether the red wavelength curve overlaps the green wavelength curve and the blue wavelength curve; and

executing the converting program if the red wavelength curve does not overlap the green wavelength curve and the blue wavelength curve.

5. The fingerprint identification method as claimed in claim 2, wherein the step of obtaining the first chromaticity coordinates corresponding to the fingerprint image further comprises:

executing the validating program to compare whether the first chromaticity coordinates meet a predetermined first color threshold.

6. A fingerprint identification device, configured to identify a fingerprint image of a finger, the fingerprint identification device comprising:

a photoelectronic sensor module, having a light receiving surface and configured for the finger to come into contact with;

at least one first light emitting element, emitting an invisible light beam toward the finger;

at least one second light emitting element, emitting a visible light beam toward the finger;

an analog/digital converter module, electrically connected to the photoelectronic sensor module; and

a processor module, electrically connected to the analog/digital converter module,

wherein the invisible light beam is reflected to the photoelectronic sensor module after passing through the finger, such that the photoelectronic sensor module receives at least one invisible light intensity signal of the invisible light beam, the visible light beam is reflected to the photoelectronic sensor module via a surface of the finger, such that the photoelectronic sensor module receives at least one visible light intensity signal of the visible light beam, the photoelectronic sensor module respectively converts the invisible light intensity signal into an invisible light photocurrent signal and converts the visible light intensity signal into a visible light photocurrent signal, the analog/digital converter module respectively converts the invisible light photocurrent signal into a first digital signal and converts the visible light photocurrent signal into a second digital signal, and the processor module respectively outputs a gray-scale fingerprint image based on the first digital signal and outputs a colored fingerprint image based on the second digital signal for identification.

7. The fingerprint identification device as claimed in claim 6, wherein the photoelectronic sensor module is formed by arranging a plurality of photoelectronic sensing elements in an array, the photoelectronic sensing elements comprise a plurality of visible light sensing chips and a plurality of invisible light sensing chips, the visible light sensing chips and the invisible light sensing chips are arranged in adjacency and form the light receiving surface.

8. The fingerprint identification device as claimed in claim 7, further comprising a scattering medium covering the light receiving surface of the photoelectronic sensor module and provided for the finger to come into contact with.

9. The fingerprint identification device as claimed in claim 6, wherein the processor module further comprises:

an analyzing program, analyzing the colored fingerprint image with a first color model to obtain first chromaticity coordinates;

a converting program, converting the first chromaticity coordinates into second chromaticity coordinates with a second color model; and

a validating program, configured to compare whether the second chromaticity coordinates meet a predetermined second skin color threshold.

10. The fingerprint identification device as claimed in claim 9, wherein processor module is configured to divide the fingerprint image into a plurality of sub-images and respectively and sequentially transmit the sub-images to the analyzing program for an analyzing process.

11. A fingerprint identification method, comprising:

placing a finger on a photoelectronic sensor module;

emitting a light beam toward the finger by a first light emitting element;

reflecting the visible light beam to the photoelectronic sensor module via a surface of the finger, such that the photoelectronic sensor module receives at least one visible light intensity signal of the visible light beam;

generating at least one visible light photocurrent signal based on the visible light intensity signal by the photoelectronic sensor module, and transmitting the visible light photocurrent signal to an analog/digital converter module by the photoelectronic sensor module;

generating at least one digital signal based on the visible light photocurrent signal by the analog/digital converter module, and transmitting the digital signal to a processor module by the analog/digital converter module; and

generating a colored fingerprint image and/or a gray-scale fingerprint image based on the digital signal and performing identification based on the colored fingerprint image and/or the gray-scale fingerprint image by the processor module.

12. The fingerprint identification method as claimed in claim 11, wherein the processor module comprises an analyzing program, a converting program and a validating program, and the step of performing identification based on the colored fingerprint image further comprises:

executing the analyzing program to analyze the colored fingerprint image with a first color model, thereby obtaining first chromaticity coordinates corresponding to the colored fingerprint image;

executing the converting program to convert the first chromaticity coordinates into second chromaticity coordinates with a second color model;

executing the validating program and comparing whether the second chromaticity coordinates meet a predetermined second skin color threshold;

determining that a fingerprint of the finger is a real fingerprint if the second chromaticity coordinates meet the second skin color threshold; and

determining that a fingerprint of the finger is a forged fingerprint if the second chromaticity coordinates do not meet the second skin color threshold.

13. The fingerprint identification method as claimed in claim 12, wherein the fingerprint image is divided into a plurality of sub-images, and the sub-images are respectively and sequentially transmitted to the analyzing program for an analyzing process.

14. The fingerprint identification method as claimed in claim 12, wherein the step of analyzing the colored fingerprint image with the first color model further comprises:

setting the first color model to be an RGB color model;

obtaining the corresponding first chromaticity coordinates based on the RGB color model, obtaining a red wavelength curve, a green wavelength curve and a blue wavelength curve based on the first chromaticity coordinates;

determining whether the red wavelength curve overlaps the green wavelength curve and the blue wavelength curve; and

executing the converting program if the red wavelength curve does not overlap the green wavelength curve and the blue wavelength curve.

15. The fingerprint identification method as claimed in claim 12, wherein the step of obtaining the first chromaticity coordinates corresponding to the fingerprint image further comprises:

executing the validating program to compare whether the first chromaticity coordinates meet a predetermined first color threshold.

16. The fingerprint identification method as claimed in claim 12, wherein the converting program further converts the color fingerprint image into the gray-scale fingerprint image, and the validating program determines whether the gray-scale fingerprint image is a real fingerprint.