Pattern metallized optical varying security devices

• US 5,757,521 A
• Filed: 11/21/1995
• Issued: 05/26/1998
• Est. Priority Date: 05/11/1995
• Status: Expired due to Fees

• Current Assignee: Advanced Deposition Technologies, Inc.
• Original Assignee: Advanced Deposition Technologies, Inc.
• Inventors: McCormick, John A., Shea, Richard C., Walters, Glenn J.
• Primary Examiner(s): Dzierzynski, Paul M.
• Assistant Examiner(s): Schuberg, Darren E.
• Application Number:
  US08/561,191
• Time in Patent Office: 917 Days
• Field of Search: 359/2, 235/441, 235/451, 235/457, 235/492, 235/380, 340/825.34, 342/6, 342/51, 380/23
• US Class Current: 359/2
• CPC Class Codes: G03H 1/0011 for security or authentication holograms on information-bearing cards B42D25/328; testing papers with holograms G07D7/0032
• CPC Class Codes: G03H 1/0236 Form or shape of the hologram when not registered to the substrate, e.g. trimming the hologram to alphanumerical shape substrates bearing a hologram G03H1/0272
• CPC Class Codes: G03H 1/0244 Surface relief holograms replicating hologram without interference recording G03H1/0276
• CPC Class Codes: G03H 2001/187 Trimming process, i.e. macroscopically patterning the hologram
• CPC Class Codes: G06K 19/0672 with resonating marks
• CPC Class Codes: G06K 19/16 the marking being a hologram or diffraction grating
• CPC Class Codes: G06K 19/18 Constructional details

Abstract

Security devices which are difficult to reproduce include a grid screen metallization pattern. The grid screen metallization pattern may be laid down over a hologram or diffraction grating formed as a surface relief pattern on a substrate, to form a visually identifiable, semi-transparent security device. Additionally, the metallization pattern may include resonant structures in which information about the security device is encoded. In some embodiments of these security devices, the metallization pattern is disposed in accurate registration with the underlying hologram or diffraction grating. These security devices are made by methods which include printing an oil pattern on the substrate. Areas on which oil is deposited do not receive metal during a metallization step. Since these methods do not use caustics, metallization patterns including features which would otherwise trap and hold caustics are possible.

Claims

1. A security device, comprising:

a substrate, one surface of which includes a surface relief pattern; and

a metallic pattern disposed thereon in registration with the surface relief pattern, so as to amplify visibility of the surface relief pattern to an observer;

wherein

the metallic pattern also forms a high frequency resonant structure.

2. The device of claim 1, further comprising:

metallic letterforms disposed on the substrate.

3. The device of claim 2, wherein the metallic letterforms are too small to be distinguished with unaided eyes.

4. A security device, comprising:

a substrate;

an integrated circuit device for controlling power supplied thereto to process a signal also supplied thereto, the integrated circuit disposed on the substrate; and

a metallic pattern disposed on the substrate and defining conductive regions on the substrate, the pattern including a means, connected to the integrated circuit, for receiving power electromagnetically coupled thereto and for supplying the power to the integrated circuit.

5. The device of claim 4, wherein the metallic pattern further comprises:

means, connected to the integrated circuit, for coupling thereto the signal.

6. The device of claim 5, wherein the signal includes high frequency electromagnetic signals, and the means for coupling further comprises:

an antenna which transmits and receives the high frequency electromagnetic signals.

7. The device of claim 4, operating in proximity to a source of electromagnetic energy, wherein the means for receiving power further comprises:

an inductive loop which receives sufficient electromagnetic energy to supply power to the integrated circuit; and

an antenna which couples the signal to the integrated circuit.

8. The device of claim 4, further comprising:

a surface relief pattern on a surface of the substrate; and

wherein

a region of the metallic pattern is disposed on the surface relief pattern in registration with the surface relief pattern, so as to amplify visibility of the surface relief pattern to an observer.

9. A method of authenticating an article, comprising the steps of:

adhering to the article a surface relief hologram;

disposing a metal pattern on the surface relief hologram so as to amplify visibility of the surface relief hologram to an observer;

illuminating the metal pattern with electromagnetic energy swept over a predetermined frequency range and at a predetermined rate; and

analyzing re-radiated electromagnetic energy to authenticate the article.

10. The method of claim 9, wherein the step of analyzing further comprises the step of:

comparing a spectrum of the re-radiated electromagnetic energy to an expected spectral signature of the metal pattern.

11. A method of authenticating an article, comprising the steps of:

adhering to the article a surface relief hologram;

disposing a metal pattern on the surface relief hologram so as to amplify visibility of the surface relief hologram to an observer;

measuring a frequency-dependent parameter of the article; and

comparing the measured frequency-dependent parameter of the article to an expected frequency-dependent parameter of an authentic article.

12. The method of claim 11, wherein the step of measuring is measuring an electrical impedance of the article at a plurality of frequencies.

13. The method of claim 11, wherein the step of measuring is measuring a plurality of reflection coefficients of the article at a corresponding plurality of frequencies.

14. A method of authenticating an article, comprising the steps of:

adhering to the article a device including a surface relief hologram;

disposing a metal pattern on the surface relief hologram so as to amplify visibility of the surface relief hologram to an observer, the metal pattern positional between the surface relief hologram and the article;

measuring capacitance of the metal pattern; and

comparing the capacitance measured with an expected capacitance.

15. The method of claim 14, further including deactivating authentication, further comprising the steps of:

forming the metal pattern of a plurality of areas connected by a fusible link; and

generating an electric current between the plurality of areas, thereby causing the fusible link to break.

16. The method of claim 15, wherein the step of generating further comprises the step of:

bringing an electric charge into proximity with the plurality of areas.

17. The method of claim 15, wherein the step of generating further comprises the step of:

applying an electric field to the plurality of areas.

18. The method of claim 15, wherein the step of generating further comprises the step of:

applying a time-varying magnetic field to the plurality of areas.

19. A pattern metalized security system, comprising:

a substrate, one surface of which includes a surface relief pattern;

a first metallic pattern disposed on the surface relief pattern so as to amplify visibility thereof to an observer; and

a probe having a plurality of capacitive plates of opposite polarity;

wherein

the first metallic pattern is disposed in such a position that a projection thereof on an outermost surface of the substrate covers an area linking at least two plates of opposite polarity of the probe.

20. The device of claim 19, further comprising:

a second metallic pattern disposed in a position electrically insulated from the metallic pattern and also having a projection on the outermost surface of the substrate linking the at least two plates of the opposite polarity of the probe.

21. The device of claim 19, wherein the first metallic pattern further comprises;

a plurality of conductive areas electrically connected by fusible links.

22. A security device, comprising:

a substrate having a surface relief pattern disposed thereon; and

a metallic pattern disposed thereon in registration with the surface relief pattern, so as to amplify visibility of the surface relief pattern to an observer;

wherein

the metallic pattern also forms elements of an electromagnetic circuit.

23. The device of claim 22, wherein a plurality of the elements formed by the metallic pattern are interconnected by a transparent conductor.

24. A security device, comprising:

a substrate having a surface relief pattern disposed thereon; and

a metallic pattern disposed thereon in registration with the surface relief pattern;

wherein

the metallic pattern forms elements of an electromagnetic circuit; and

further wherein

a plurality of the elements formed by the metallic pattern are interconnected by a readily oxidizable substance disposed on a surface of the substrate.

25. The device of claim 24, further comprising:

a layer of adhesive disposed on the surface of the substrate and protecting the readily oxidizable substance disposed thereon from exposure to ambient atmosphere.