Biometrics authentication system

• US 8,335,353 B2
• Filed: 04/03/2008
• Issued: 12/18/2012
• Est. Priority Date: 04/04/2007
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamamoto, Kenji, Ichimura, Isao
• Primary Examiner(s): Tucker, Wesley
• Assistant Examiner(s): Bitar, Nancy
• Application Number:
  US12/450,120
• Publication Number:
  US 20100092047A1
• Time in Patent Office: 1,720 Days
• Field of Search: 382/124, 382/115, 382/116, 345/82
• US Class Current: 382/115
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/14 Vascular patterns

Abstract

A low-profile biometrics authentication system capable of achieving high security level authentication is provided. A biometrics authentication system 1 includes a light source 10, a light guide section 11A, a diffraction section 11B, a microlens array 12, an image pickup device 13, an image processing section 14, a pattern storing section 15, an authentication section 16, a voltage supply section 17, a light source driving section 181, an image pickup device driving section 182 and a control section 19. When light L0 emitted from the light source 10 propagates through the light guide section 11A by total reflection, and then enters the diffraction section 11B, light L1 diffracted at a different angle from an incident angle is generated. Thereby, the light guide section 11A functions as a surface-emitting light source, and total reflection conditions in the light guide section 11A are not satisfied, and the light L1 is guided to the outside of the light guide section 11A, thereby light is sufficiently applied to the inside of the living body 2.

Claims

1. A biometrics authentication system comprising:

a light source;

a detection section where a living body is placed;

a light guide section totally reflecting light emitted from the light source to guide the light to the living body;

a diffraction section diffracting light propagating through the light guide section, the diffraction section including a plurality of groove sections with each groove section having a depth, the depths of the groove sections are adjusted so that a diffraction efficiency of the diffraction section changes with respect to the distance from the light source;

an image pickup lens section condensing light from the living body and including a micro lens array having a plurality of micro lenses, the micro lens array operative to change its refractive characteristics;

an image pickup device obtaining image pickup data based on the light condensed by the image pickup lens section; and

an authentication section performing authentication of the living body based on the image pickup data obtained in the image pickup device.

2. The biometrics authentications system according to claim 1, wherein

the light guide section is arranged in a region opposed to the detection section between the detection section and the image pickup lens section.

3. The biometrics authentication system according to claim 2, wherein

the diffraction section is arranged on a surface on the image pickup lens side of the light guide section so as not to be opposed to the detection section.

4. The biometrics authentication system according to claim 2, wherein

the living body is a finger, and

the light guide section is arranged so as to allow light emitted from the light source to propagate along a longer direction of the finger.

5. The biometrics authentication system according to claim 2, wherein

the diffraction section diffracts only a specific polarized component of light propagating through the light guide section, and

the biometrics authentication system includes a ¼

wave plate between the detection section and the light guide section, the ¼

wave plate arranged opposed to the diffraction section.

6. The biometric image pickup apparatus according to claim 2, wherein

the diffraction section and the image pickup lens section are arranged on a common plane and project therefrom in a same direction.

7. The biometrics authentication system according to claim 6, wherein

the image pickup lens section is integrally formed with the light guide section on a condensing optical path.

8. The biometrics authentication system according to claim 6, wherein

the image pickup lens section is made of a diffraction lens.

9. The biometrics authentication system according to claim 1, wherein

the light guide section is arranged in a region which is in proximity to the detection section but is not opposed to the detection section.

10. The biometrics authentication system according to claim 9, wherein

the living body is a finger, and

the light guide section is arranged only in a region on one side of the detection section along the longitudinal direction of the detection section.

11. The biometrics authentication system according to claim 9, wherein

the living body is a finger, and

the light guide sections are arranged in regions on both sides of the detection section along the longitudinal direction of the detection section.

12. The biometrics authentication system according to claim 9, wherein

the living body is a finger, and

the light guide section is arranged so as to surround the detection section.

13. The biometrics authentication system according to claim 9, wherein

a diffraction surface of the diffraction section is arranged on a side surface of the light guide section.

14. The biometrics authentication system according to claim 1, wherein

the living body is a finger, and

the light guide sections are arranged at both ends in the longitudinal direction of the detection section so as to be opposed to the detection section.

15. The biometrics authentication system according to claim 14, wherein

a region not opposed to the light guide section of the detection section is an image pickup region by the image pickup lens section and the image pickup device.

18. The biometrics authentication system according to claim 1, wherein

the depths of the groove sections are adjusted so that the diffraction efficiency of the diffraction section is increased with increase in distance from the light source.

19. The biometrics authentication system according to claim 1, wherein

the light sources are arranged at both ends of the light guide section.

20. The biometrics authentication system according to claim 1, comprising:

a voltage supply section for applying a voltage to the microlenses,

wherein the microlenses make the diffraction directions of incident light rays variable according to a voltage applied by the voltage supply section.

21. The biometrics authentication system according to claim 20, wherein

the image pickup lens section is configured to include:

a pair of substrates,

a pair of electrodes formed on the substrates, the pair of electrodes to which a voltage from the voltage supply section is applied, and

a liquid crystal layer arranged between the pair of electrodes,

wherein one or both of the pair of electrodes have curved surfaces for forming the microlenses.

22. The biometrics authentication system according to claim 1, wherein

the light source emits light in a near-infrared wavelength region.

23. The biometrics authentication system according to claim 1, wherein

the living body is a finger,

the image pickup device produces image pickup data of veins of the finger, and

the authentication section performs authentication of the living body based on the image pickup data of the veins.

24. The biometrics authentication system according to claim 1, further comprising a controller and a voltage supply section for applying a voltage to the microlenses such that the controller controls the voltage supply section in a manner to cause the voltage supply section to provide a relatively large voltage to the microlenses resulting in a relatively large refractive index, a relatively large refractive angle and a relatively short focal length or a relatively small voltage to the microlenses resulting in a relatively small refractive index, a relatively small refractive angle and a relatively long focal length.

16. A biometrics authentication system comprising:

a light source;

a detection section where a living body is placed;

a light guide section totally reflecting light emitted from the light source to guide the light to the living body;

a diffraction section diffracting light propagating through the light guide section;

an image pickup lens section condensing light from the living body;

an image pickup device obtaining image pickup data based on the light condensed by the image pickup lens section; and

an authentication section performing authentication of the living body based on the image pickup data obtained in the image pickup device, wherein

a diffraction surface of the diffraction section is arranged on a surface on the image pickup lens side of the light guide section;

the diffraction section includes a plurality of groove sections with each groove section having a depth, the depths of the groove sections are adjusted so that a diffraction efficiency of the diffraction section changes with respect to the distance from the light source.

17. The biometrics authentication system comprising:

a light source;

a detection section where a living body is placed;

a light guide section totally reflecting light emitted from the light source to guide the light to the living body;

a diffraction section diffracting light propagating through the light guide section;

an image pickup lens section condensing light from the living body;

an image pickup device obtaining image pickup data based on the light condensed by the image pickup lens section; and

an authentication section performing authentication of the living body based on the image pickup data obtained in the image pickup device, wherein

the diffraction section is configured so that its diffraction efficiency is increased with increase in distance from the light source.