Uneven-surface data detection apparatus

• US 4,728,186 A
• Filed: 02/27/1986
• Issued: 03/01/1988
• Est. Priority Date: 03/03/1985
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yahagi, Hironori, Ikeda, Hiroyuki, Yamagishi, Fumio, Eguchi, Shin, Igaki, Seigo, Inagaki, Takefumi
• Primary Examiner(s): Rosenberger, R. A.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/833,276
• Time in Patent Office: 733 Days
• Field of Search: 356/71, 356/448, 382/4
• US Class Current: 356/71
• CPC Class Codes: G02B 6/26 Optical coupling means G02B6/36, G02B6/42 take precedence
• CPC Class Codes: G02B 6/3522 the optical element enabling or impairing total internal reflection using evanescent coupling G02B6/3536
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/40 Spoof detection, e.g. liveness detection
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

An uneven-surface data detection apparatus, includes a transparent plate having an uneven-surface contact portion against which an uneven surface to be detected is pressed. A light source illuminates the uneven-surface contact portion through the transparent plate. An uneven-surface image drawing out optical element draws out the light reflected on the uneven-surface contact portion of the transparent plate. A detector detects the light drawn out from the transparent plate by the optical element.

Light reflected by a projection-facing portion of the uneven surface contact portion to be introduced into the detector diverges from a propagation direction of light reflected by a recess-facing portion of the uneven surface contact portion. The optical element is arranged to guide the light reflected by the projection-facing portion into the detector.

Claims

1. An uneven-surface data detection apparatus for detecting an uneven-surface having projection portions and recess portions, comprising:

a transparent plate having upper and lower surfaces and having an uneven-surface contact portion against which an uneven-surface to be detected is pressed;

a light source for illuminating the entire area of said uneven-surface contact portion through said transparent plate;

an uneven-surface image drawing out optical element for drawing out the light reflected on said uneven-surface contact portion of said transparent plate; and

a detector for detecting the light drawn out from said transparent plate by said optical element, light reflected by the projection portions of said uneven-surface on said uneven-surface contact portion diverges from a propagation direction of light reflected by the recess portions of said uneven-surface on said uneven-surface contact portion, and said optical element is arranged to guide the light reflected by said projection portions into said detector, said light source simultaneously illuminating said projection portions and recess portions over said uneven-surface contact portion and the light reflected by said projection portions being totally reflected at least one time at a surface opposite the surface where the uneven-surface contact portion is located and then guided to said detector through said uneven-surface image drawing out optical element.

2. An apparatus according to claim 1, wherein said light source illuminates said uneven-surface contact portion at an illumination angle smaller than a critical angle so as not to totally reflect the light, wherein part of the light scattered by said projection is totally reflected at least once in said transparent plate so as to propagate through said transparent plate in a direction of said optical element, and wherein light, which passes through said transparent plate, illuminates said recess and is scattered thereby, re-enters said transparent plate to be discharged therefrom at the lower surface, thereby discriminating the scattered light from the totally reflected light.

3. An apparatus according to claim 1, wherein said optical element is a hologram.

4. An apparatus according to claim 1, wherein said optical element is a prism.

5. An apparatus according to claim 2, wherein said light source substantially vertically illuminates said uneven-surface contact portion from below.

6. An apparatus according to claim 2, wherein said light source illuminates said uneven-surface contact portion through said transparent plate at an angle falling within a range of -38°

to +33°

with respect to the upper surface of said plate, a vertical direction is considered a 0° and

a direction toward said optical element is represented by negative direction.

7. An apparatus according to claim 1, wherein a hologram is arranged on the lower surface of said transparent plate, wherein said uneven-surface contact portion is illuminated with said light source at an illumination angle smaller than a critical angle so as not to totally reflect light, wherein the recess portions scatter light which is guided from the lower surface of said transparent plate to be diffracted in a direction of said detector, and wherein said hologram is arranged such that said light source illuminates the recess portions and the light therefrom is scattered, re-enters said transparent plate and is diffracted by the lower surface of said transparent plate in a direction other than that of said detector.

8. An apparatus according to claim 1, wherein said light source is an LED which illuminates said uneven-surface contact portion through a Lippmann hologram.

9. An apparatus according to claim 1, wherein a dust cover is arranged on at least one of the upper and lower surfaces of said transparent plate forming an air layer therebetween.

10. An apparatus according to claim 1, wherein an elastic member is arranged on the upper surface of said uneven-surface contact portion of said transparent plate.

11. An apparatus according to claim 1, further comprising:

a personal verification system including;

data verification means; and

a data verification dictionary connected to said data verification means; and

bio-detecting means, connected to said data verification means, for discriminating if the uneven-surface to be detected is a living body.

12. An apparatus according to claim 11, wherein said bio-detecting means comprises:

first photodetecting means for detecting visible light at a short wavelength between 440 to 580 nm and generating an output signal;

second photodetecting means for detecting light at a wavelength longer than 630 nm;

reference voltage generating means, operatively connected to said second photodetecting means, for generating a reference voltage in response to an output voltage from said second photodetecting means; and

comparing means, operatively connected to said first photodetecting means, for comparing the reference voltage with an output voltage from said first photodetecting means.

13. An apparatus according to claim 1, wherein said optical element is a hologram, and further comprising:

a first cylindrical lens for focusing a virtual image focused at a vertical focal point, arranged opposite said hologram and having an axis parallel to an expansion direction of the virtual image at the horizontal focal point due to aberration; and

a second cylindrical lens for focusing a virtual image focused at a horizontal focal point, arranged opposite said hologram and orthogonal to said first cylindrical lens and having an axis parallel to an expansion direction of the virtual image at the vertical focal point due to aberration.

14. An apparatus according to claim 13, wherein said hologram is produced by interference of plane waves, and a combination of said first and second cylindrical lenses satisfies a relation:

space="preserve" listing-type="equation">dz=(M1+1).sup.2 /M1) f1-((M2+1).sup.2 /M2) f2

where f1 and f2 are focal lengths of said first and second cylindrical lenses, respectively, M1 is a lateral magnification, M2 is a longitudinal magnification, and dz is an astigmatic difference.

15. An apparatus according to claim 13, further comprising spatial filters parallel to the axes of said first and second cylindrical lenses and arranged at focal points of said first and second cylindrical lenses for eliminating image blurring.

16. An apparatus according to claim 1, further comprising a plurality of holograms provided on said transparent plate, and arranged at equal distances from said uneven-surface contact portion, a plurality of identical uneven-surface data being obtained from said holograms.

17. An apparatus according to claim 1, wherein said light source illuminates said uneven-surface contact portion at an illumination angle larger than a critical angle so as to be totally reflected and the light is scattered at the projection portions, and wherein the scattered light propagates in a direction different from the illumination direction and is detected by said detector.

18. An apparatus according to claim 2, wherein said optical element is a hologram.

19. An apparatus according to claim 2, wherein said optical element is a prism.

20. A detector apparatus comprising:

a transparent base having a contact portion;

means, located adjacent to a first side surface of said transparent base, for illuminating said transparent base with light;

means, formed adjacent to a second side surface of said transparent base opposite the first side surface, for guiding the light from said means for illuminating to said contact portion of said transparent base, the light beam being totally reflected from portions of said contact portion;

means, located on a bottom surface of said transparent base and adjacent to the first surface side of said transparent base, for focusing the totally reflected light from said contact portion and for outputting the focused light; and

detector means, located adjacent said focusing means, for receiving the focused light and detecting an object on said contact portion.

21. A detection apparatus comprising:

a transparent base having a contact portion formed on a top surface, said contact portion including projection portions;

means, located adjacent a side surface of said transparent base, for illuminating said contact portion of said transparent base with light and totally reflecting the light from said projection portions of said contact portion;

means, formed on said transparent base, for guiding the totally reflected light from said means for illuminating said contact portion of said transparent base;

means, formed on said transparent base, for focusing the totally reflected light from said projection portions of said contact portion and for outputting the focused light; and

detector means, located adjacent to said focusing means, for receiving the focused light and detecting an object on said contact portion.

22. A detection apparatus according to claim 21, wherein said means for illuminating is located adjacent a surface of said transparent base on which said means for focusing is located.

23. A detection apparatus according to claim 22, wherein said means for guiding the light from said means for illuminating said contact portion is located on a side surface of said transparent base opposite said means for illuminating and adjacent to said contact portion of said transparent base.

24. A detection apparatus according to claim 21, wherein said means for guiding the light from said means for illuminating said contact portion is located on a bottom surface of said transparent base opposite the top surface on which said contact portion is formed.

25. A detection apparatus according to claim 24, wherein said means for illuminating is located adjacent a side surface of said transparent base closest to said means for guiding the light and opposite said detector means.

26. A detection apparatus according to claim 21, wherein said means for illuminating is an LED.

27. A detection apparatus according to claim 21, wherein said means for guiding the light is a Lippmann hologram.

28. A detection apparatus according to claim 21, wherein said means for focusing is a hologram.

29. A bio-detection optical system comprising:

a base having a contact portiin formed thereon;

means, located on one side of the contact portion, for detecting light having a short wavelength and outputting an output voltage; and

means, located on the other side of said contact portion and opposite said means for detecting light having a short wavelength, for detecting light having a long wavelength and outputting an output voltage.

30. A bio-detection optical system according to claim 29, wherein said means for detecting light having a short wavelength and said means for detecting light having a long wavelength are capable of moving in a direction orthogonal to said contact portion, and each of said means comprising:

a photosensor; and

a light emitting diode located adjacent to said photosensor.

31. A bio-detection optical system according to claim 30, further comprising:

means, operatively connected to said means for detecting light having a long wavelength, for generating a reference voltage in response to the output voltage from said means for detecting light have a long wavelength;

means, operatively connected to said means for generating a reference voltage and said means for detecting light having a short wavelength, for comparing the reference voltage with the output voltage from said means for detecting light having a short wavelength.

32. A bio-detection optical system according to claim 31, wherein said comparing means comprises:

a bio-discrimination comparator operatively connected to said means for generating a reference voltage; and

a contact detection comparator, operatively connected to said means for generating a reference voltage, for detecting when said means for detecting light having a long wavelength contacts the object on said contact portion.

33. A bio-detection optical system according to claim 32, wherein said means for detecting light having a short wavelength detects light having a wavelength within a range of 440 nm to 580 nm, and wherein said means for detecting light having a long wavelength detects light having a wavelength longer than 630 nm.