SYSTEM FOR IDENTIFYING PERSONNEL BY FINGERPRINT VERIFICATION AND METHOD THEREFOR

• US 3,743,421 A
• Filed: 07/02/1971
• Issued: 07/03/1973
• Est. Priority Date: 07/02/1971
• Status: Expired due to Term

• Current Assignee: William T. Maloney
• Original Assignee: William T. Maloney
• Inventors: Maloney, William T.
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): McGraw, V. P.
• Application Number:
  US05/159,382
• Time in Patent Office: 732 Days
• Field of Search: 356/71,164,165,166,168 250/219CR,219DQ 340/146.3E
• US Class Current: 356/71
• CPC Class Codes: G06V 10/88 Image or video recognition using optical means, e.g. reference filters, holographic masks, frequency domain filters or spatial domain filters
• CPC Class Codes: G06V 40/12 Fingerprints or palmprints
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

An optical recognition device which employs a source of incoherent quasi-monochromatic light for illuminating an input prism upon which a fingertip to be verified as that of a particular individual is pressed. Reflected incoherent illumination from the prism is passed through a hologram selected from a library of holograms which contains interference patterns produced from the fingertip or an impression of the fingertip of the particular individual. An intensity output signal provided at the hologram output is directed to a discriminator which passes the central value signal of the intensity output signal and a detector responsive to the central value of the intensity signal provides an electrical current output which is coupled into a signal processor. The signal processor has threshold levels which correspond to values of electrical current signals required to establish correspondence between the reflected incoherent illumination from the input prism with the fingertip pressed against it and the interference patterns contained in the hologram. The signal processor produces an output signal which indicates correspondence between the fingertip pressed against the input prism and the fingertip represented by the interference patterns.

Claims

1. A lensless optical recognition device for identifying personnel by fingerprint verification comprising, a source of quasi-monochromatic incoherent illumination, input means illuminated by said quasi-monochromatic incoherent illumination in which a fingertip to be verified as the fingertip of a particular individual is pressed against said input means, holographic means having interference patterns produced from said fingertip or an impression of said fingerprint of said particular individual, said holographic means providing an intensity output signal in response to said incoherent illumination reflected from said input means, discriminator means for receiving said intensity output signal and passing a central value signal corresponding to the central value of said intensity output signal, detector means responsive to said central value signal passed by said discriminator means for providing an electrical output signal in accordance with said central value signal, and signal processing means coupled to said detector means having threshold levels which correspond to values of electrical signals required to establish correspondence between said reflected incoherent illumination and said interference patterns, said signal processing means providing an output signal in response to said electrical output signal thereby verifying that said fingertip pressed against said input means is the same as said fingertip represented in said holographic interference pattern.

2. A lensless optical recognition device as described in claim 1 in which said holographic means includes interference patterns from fingertips of a plurality of known individuals including said particular individual.

3. A lensless optical recognition device as described in claim 1 which includes optical means disposed between said input means and said holographic means for rotating and translating said reflected incoherent illumination with respect to said holographic means.

4. A lensless optical recognition device as described in claim 3 in which said optical means includes a dove prism.

5. A lensless optical recognition device as described in claim 1 which includes means for rotating said holographic means, said discriminator means and said detector means simultaneously with respect to said input means.

6. A lensless optical recognition device as described in claim 1 which includes means for rotating and translating said holographic means, said discriminator means and said detector means simultaneously with respect to said input means.

7. A lensless optical recognition device as described in claim 1 which includes optical fiber transmission lines coupled between said discriminator means and said detector means.

8. A lensless optical recognition device as described in claim 7 which includes means for rotating and translating said holographic means and said discriminator means simultaneously with respect to said input means.

9. A lensless optical recognition device for identifying personnel by fingerprint verification comprising, a source of quasi-monochromatic incoherent illumination, input means illuminated by said quasi-monochromatic incoherent illumination in which a fingertip to be verified as the fingertip of a particular individual is pressed against said input means, holographic means having interference patterns produced from positive and negative transparencies of impressions of said fingertips of said individual, said holographic means providing a first central intensity signal and a second central intensity signal in response to said incoherent illumination reflected from said input means, discriminator means for passing a first central value signal corresponding to the central value of said first central intensity signal and a second central value signal corresponding to the central value of said second central intensity signal, detector means for producing a first electrical output signal in response to saiD first central value signal and a second electrical output signal in response to said second central value signal, and signal processing means coupled to said detector means having a first channel which includes threshold levels that set a lower limit to said first electrical output signal and a second channel which includes threshold level that set an upper limit to said second electrical output signals for providing unambiguous correspondence between said reflected incoherent illumination and said interference patterns, said signal processing means providing an output signal indicative of the verification that said fingertip pressed against said input means is the same as said fingertip represented in said holographic means.

10. A lensless optical recognition device as described in claim 9 which includes optical means disposed between said input means and said holographic means for rotating and translating said reflected incoherent illumination with respect to said holographic means.

11. A lensless optical recognition device as described in claim 10 in which said optical means includes a dove prism.

12. An optical recognition device for identifying personnel by fingerprint verification, comprising holographic means having interference patterns produced from positive and negative transparency impressions of a fingertip of a particular individual, a point source of quasi-monochromatic illumination disposed with respect to said holographic means in the same position as said fingertip during recording of said positive and negative transparencies for producing colored images from said positive and negative transparencies a second source of illumination, input means illuminated by said second source of illumination in which a fingertip of said particular individual having said fingerprint to be verified is pressed against said input means, optical means for receiving reflected illumination from said fingerprint at said input means and producing an erect image of said fingerprint, means for superimposing said erect image of said fingerprint to be verified on first said colored image produced from said positive transparency and second on said colored image produced from said negative transparency, filter means disposed between said optical means and said erect image of said unknown fingerprint for producing an erect image of said unknown fingerprint having a color that is complementary to said colored images produced from said positive and negative transparencies, and display means to receive superimposed colored images of said unknown fingertip, said positive transparency and said negative transparency of said fingertip of a particular individual which indicates the correspondence between the fingertip pressed against the input means and said fingertip represented by said interference pattern in said holographic means.

13. An optical recognition device for identifying personnel by fingerprint verification as described in claim 12 in which said optical means for receiving reflected illumination from said fingerprint includes a lens for producing an inverted image on a reflecting surface and said reflecting surface produces an erect image of said fingerprint.

14. An optical recognition device for identifying personnel by fingerprint verification as described in claim 12 in which said means for superimposing said erect image on first said image produced from said positive transparency and second on said image produced from said negative transparency includes control means for translating and rotating said means for superimposing.

15. A method for identifying personnel by fingerprint verification comprising the steps of applying an unknown fingerprint to be verified as the fingerprint of a known individual against an input means, illuminating a hologram with a point source of quasi-monochromatic light, said hologram containing interference patterns produced from a plurality of fingerprints of known indivIduals and said illumination provides a plurality of positive images of a first color, each of said images corresponding to a known fingerprint, illuminating said input means with light to produce a positive image corresponding to said unknown fingerprint of a second color that is complementary to said first color, sequentially superimposing said positive image corresponding to said unknown fingerprint upon each of said plurality of positive images corresponding to said known fingerprints, and verifying that said unknown fingerprint corresponds to one of said known fingerprints by observing the absence of said first and second colors when said image from said unknown fingerprint is superimposed upon an image from said known fingerprints that corresponds to said image from said unknown fingerprint.

16. A method for identifying personnel by fingerprint verification as described in claim 14 wherein said step of illuminating a hologram with quasi-monochromatic light provides a plurality of negative images, said step for sequentially superimposing said positive image provides for sequentially superimposing said positive image upon each of said plurality of negative images, and said step for verifying is performed by observing the presence of said first and second colors when said positive image from said unknown fingerprint is superimposed on negative image from said known fingerprints that corresponds to said image from said unknown fingerprint.

17. A method for identifying personnel by fingerprint verfication as described in claim 14 wherein the step of illuminating a hologram with quasi-monochromatic light provides a plurality of positive and negative images, said step for sequentially superimposing said positive image corresponding to said unknown fingerprint provides for sequentially superimposing said positive image upon first said positive image and second said negative image of each pair of positive and negative images of said plurality of positive and negative images, and said step for verifying is performed by observing first the absence of said first and second colors when said image from said unknown fingerprint is superimposed on positive image from said known fingerprints and by observing the presence of said first and second colors when said image from said unknown fingerprint is superimposed upon negative image from said known fingerprints.

18. A method for identifying personnel by fingerprint verification as described in claim 16 wherein the step of illuminating a hologram with a point source of quasi-monochromatic light produces positive and negative images of a first color which correspond to the interference patterns in the hologram that represent a fingerprint of a single known individual.