Claims
- 1. A scanner for extracting information from a security device on a surface, said scanner comprising:a light source constructed to generate a light beam having a predetermined temporal modulation; focusing optics to direct the light from the light source to illuminate a spot on the security device; spectrally dispersive optics to collect light that is at least one of diffracted, scattered and emitted from the spot on the security device and focus the collected light to a spectrum, and a time-gated sensor to detect a time-dependent distribution of light in the spectrum.
- 2. The scanner of claim 1 wherein the time-dependent distribution of light in the spectrum is compared to a set of template distributions.
- 3. The scanner of claim 1, wherein the time gated sensor detects a series of spectra of light emitted by particles in said security device due to the illumination of a corresponding series of spots on the security device.
- 4. A security system comprising:an arrangement of light-emitting particles on a surface, said arrangement forming a pattern of varying spectral emission properties corresponding to each of the light emitting particles applied to an object a scanner for extracting information from the security device, said scanner comprising: a light source constructed to generate a light beam having a predetermined temporal modulation; focusing optics to direct the light from the light source to illuminate a spot on the security device; spectrally dispersive optics to collect light that is at least one of diffracted, scattered and emitted from the spot on the security device and focus the collected light to a spectrum, and a time-gated sensor to detect a time-dependent distribution of light in the spectrum; and a mover that changes a location of said illuminated spot relative to the security device.
- 5. The system of claim 4, further comprising a recorder that records the spatially varying spectral emission properties of the security device, and wherein said arrangement of kinds of particles in the security device further comprises a representation of information.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of pending U.S. patent application Ser. No. 09/881,409, filed Jun. 13, 2001 now U.S. Pat. No. 6,535,638, which is a continuation of U.S. patent application Ser. No. 09/224,260, filed Dec. 31, 1998 now U.S. Pat. No. 6,263,104.
US Referenced Citations (10)
Foreign Referenced Citations (3)
Number |
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0 549 990 |
Jul 1993 |
EP |
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Continuations (2)
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Number |
Date |
Country |
Parent |
09/881409 |
Jun 2001 |
US |
Child |
10/368120 |
|
US |
Parent |
09/224260 |
Dec 1998 |
US |
Child |
09/881409 |
|
US |